well, the twilight cleric seem a solid pick with the war wizard,6th level is a long time to go for a payoff like this and until then you are building a melee character that is not good at melee. I would look at other options, based on cleric base class.
Instead of Arcane cleric, take a cleric that gives heavy armor and dip into wizard, sorcerer or warlock for the cantrips. A twilight cleric in particular with 1 level in one of these would IMO be better for what you are trying to do and would come online quicker, especially since you can take thewarcaster feat at 1st level and get superior darkvision to boot.
As far as being MAD you don't need all that constitution if you get heavy armor and a shield and the shield spell and absorb elements and warcaster ....... and you can have all that at level 2. So you can easily drop constitution to 12 and dexterity to 10/8 to get the strength and inteligence or charisma you need and you will have a more well rounded character that is as good or better in combat.
Personally I like wizard for this build because of the rituals, I would also eventually go to 2nd level and take war mage - cleric 1, wizard 1, cleric 5, wizard 2, cleric x.
SAD was not a big priority, actually i was going with the hexblade for grasp of hadar more than darkvision, but having to get the grasp that devil sight was good as well. The reason were that with grasp of hadar i still have a good damage even when i want to pull creatures in the SG area, without grasp of hadar i have to take care of it with lightining lure, that have lower damage and lower range (and especially the range seem maybe too short for work with effectivenes).
Nature cleric would solve this as it can get thorn whip for a 30 ft range and heavy armors, but it has no darkvision.
so thats how i got till grasp of hadar and devil's sight from warlock, and than from here, i thought about the divine soul sorcerer for the SAD part.
Anyway i really like the twilight cleric/war wizard, great saves, great AC, great initiative, hight DPR and a good action economy (except for reactions where it have always to choose if save it for shield or get an OA (at least if he get sentinel).
it can go with 16 str, 8 dex, 12 con, 13 int, 16 wis, 8 cha
feats warcaster, +2 wis, +2 wis, sentinel
i suppose he want to cast spiritual weapon in his 2nd turn
But how do you think i can solve the problem with the range of lightniing lure? Having only 15 ft, once they are out from SG area, it cant reach them without move, but moving it can lose other creatures in the range, and anyway once he move he dont need anymore lightning lure as they are again in the area...is it just not so important and i can forget those cantrips for move and bring them in the area? Or its something that need to be fixed somehow?
PS do you think guardian of faith should enter in this build? As action economy will be 1) spirit guardian, 2) Bonus action spiritual weapon + BB attack, 3) can be bonus action attack wth spiritual weapon + cast guardian of faith...but i dont know how much its good to cast it on turn 3, it could be litteraly a waste of a kinda hight lv slot, while if i cast it before i can argue the same about SW be casted on turn 3. So im really not sure its something to pick with this character or not, because would be very thematic for the character that i have in mind, and also the twilight cleric have some good point, but i neither want to pick it for never play it because it enter too late for be considered a good cost/profit investement in terms of action economy, because even if i want to think about alternate SW and GoF, seem it dont work so much, because "bonus action attack with SW + cast guardian of faith" is nice, stay 2 turns casting SG and GoF and do nothing else maybe its not nice as well. All considering anyway that my fights are kinda few, 2, no more than 3 a day, sometimes even 1.
Would be nice to have sort of kite action for trigger additional damage from BB once they move for reach me, crusher seem work well for it, as it dont require any kind of action except attack, but the stats would have some problem with it i suppose...half feats and humans seem dont match that much lol...the one way seem start with str 15 and than get crusher at lv 4, leaving str to 16 (probably for another +1 int for initiative or a dex to 10 instead than 8) and wis to 18, insted than 18 str and 18 wis or 16 str and 20 wis. Also about this tactic, im not that sure its totally worth, as while it trigger the additional damage from BB, it allow them to go out from SG area without get an OA.