D&D 5E Variant Human Battlemaster/War Cleric Optimization

Concept:
Variant Human
Battlemaster Fighter/War Domain Cleric
Maul

That is my core concept. I feel it works well thematically and has a enough synergy to get by in combat.

Builds:
I've come up with a number of possible builds and am open to others as long as we stick to my core concept.

Battlemaster 3/ War Cleric 17 - Have your maneuvers and your level 9 spell too. Not as many attacks, but way more spellcasting capability.

Battlemaster 11/ War Cleric 9 - Three attacks and still gets level 5 spells, which are very nice.

Battlemaster 12/ War Cleric 8 - Still three attacks but you lose level 5 spells for another feat or attribute bump.

Progression:
Str:16
Dex: 8
Con: 16
Int 8:
Wis: 16
Cha: 8

Variant Human: Heavy Armor Master
This feat brings us a stat bump that allows us to start with three 16s (Str, Con, Wis) in our attributes and a damage reduction ability that is extremely good for quite a while. Great Weapon Master looks very good for the 3/17 build, but even for that one, I'm not sure it's as good as Heavy Armor Master to start with.

(Level 1) Fighter 1: Fighting Style, Second Wind
The thinking behind taking a level of fighter first is getting the Fighter saving throw proficiencies locked in. Fighter also gets you a self-heal and the Great Weapon Fighting style as well. Defense style is actually a second choice probably, because we'll be attacking enough to make GWF well worth it, I think. What do we lose out on for starting Fighter? Mostly just the ability to take War Caster as our first feat, which sets getting it back significantly.

(Level 2) Cleric, War Domain 1: Spellcasting, Divine Domain, War Priest
We can now enhance our combat abilities or heal with spells. We also get a limited source of multiple attacks. This is probably our primary source of multiple attacks for 3/17 , but for 11/9 and 12/8 it will simply tide us over until we can get to Fighter 5.

Here's where it gets tricky.... How do we progress from here?
What is the best maul-weilding Human Battle Master/ War Cleric build and the best way to progress through it? Should I use those attributes or raise some of those 8s and lower something else? Take Great Weapon Master first? Any kind of advice you can offer is appreciated.

My current character if a Battlemaster Fighter / Light Cleric, so pretty close to what you have. If I could, I would switch the Domain to War, but the last time I checked my DM veto'd the notion.

Personally I serve as the group's tank and combat medic, so for Fighting Style I definitely went with Defensive. I also use Sword and Shield over the 2-Hander like you are planning. I started out using a Greatsword, but I was also dropping every encounter. Plus finding a magical shield makes it hard to turn down +3 AC for turning a d8 into 2d6.

As far as leveling goes, whichever route you pick after 1 Fighter and 1 Cleric, you are probably going to want to ride it until you get 5 Levels in it. If its Fighter, you're going to want the 4th Level ASI and the 5th Level Extra Attack...and if you are already level 5 then you are just 1 more level away from the Fighter's 6th level ASI. That locks you into Fighter for a LONG time, and your Cleric levels will not scale great. You'll get some utility from using the War Domain's Bonus Attack, and Healing Word to pick up a downed ally, but nothing else is going to scale great (although I use Sacred Flame A LOT instead of having to carry around a ranged weapon).

If you go Cleric to 4th to get your ASI, then you may as well take it to 5th for access to 3rd Level Spells. At this point, however, you are definitely more of a caster than anything else. In fact at best you are a "Battlemage", and it will be 2 more levels (CL8) before you can even get Battlemaster for the fun maneuvers. Your Extra Attack won't come in until CL10 at the earliest as well.

So it really depends on how you end up playing your character. In my group, I couldn't see myself going Cleric over Fighter and having as much success defending my group. Your circumstances might be different though. But personally, I've LOVED the Fighter-centric Cleric. F6/C1 will next be F6/C2, and I am thinking of riding Cleric out from here.

This is what I decided based on creating synergy and getting the most out of class features, rather than stacking redundant bonus actions. What I wound up with is a Cleric that can hang in melee and dish out some significant damage with their weapon. Pretty good AC between heavy armor and spells and can heal themselves as needed.

The build will eventually be Battlemaster Fighter 3/War Cleric 17. Something to note is that this character does particularly well with Advantage, so it's a good idea go for that Inspiration when playing it.

Starting Out
Race: Variant Human

Class: Fighter 1

Attributes: Str 16, Dex 8, Con 14, Int 8, Wis 16, Cha 10 (Point Buy)

Feats: Great Weapon Master

Fighting Style: Great Weapon Fighting

Skills: Perception, Insight, Athletics, Intimidation, Persuasion

Progression
1: It's all about getting those saving throws. Gotta go Fighter 1. Great Weapon Fighting style is very powerful with a 2d6 damage weapon such as Maul or Greatsword. We'll be out-damaging most characters right out of the gate. Bonus self-healing feature with Second Wind.

1/5: After we take that first level of fighter, we need to go Cleric for at least 4 levels for the Warcaster feat. Probably 5 levels though for those two 3rd level spells. This gets us all kinds of other great stuff, including our main source of multiple attacks for the build and our AC boosting spells. We can now channel divinity to make sure our big damage attacks hit too.

3/5: Maneuvers are going to be the next thing probably, but we actually get good stuff like Action Surge for our effort too. Maneuvers: Riposte for reaction-based extra attacks, Precision Attack to make more big damage attacks hit, and probably Goading Attack for the battlefield control.

3/17: Ride it out with Cleric. Some of our War Domain abilities will help out quite a bit and it's all about those spells that enhance and sustain us in battle. Ability Score increases at 11, 15, and 19. Con+2, Wis+2, Str+2 in that order probably. We need that hitpoint and save increase from Constitution. Wisdom increases our pool of multiple attacks and is our spellcasting attribute. To be effective at high levels, we should increase it at least once. Strength to keep up on damage and to take advantage of the fact that we are attacking in melee 2-3 times a round fairly consistently between War Priest, Action Surge, Great Weapon Master and Riposte. A handful of them will be Great Weapon Master power attacks using Guided Strike and/or Precision Attack to make sure they hit. We also get Divine Strike, which gives those attacks we make on our turn an extra 2d8 damage.

After a brief playtest, I've decided that the build benefits more from Defense fighting style than Great Weapon Fighting. GWF is as good as I thought, but it is a luxury to do a little extra damage, whereas any constant boost to AC for this character is strait up gold.