In an actual real game? Close enough also counts the level doesn't need to be exact
Eldritch Knight 6, Bladesinger 2
I have played this and regretted it. This is substantially weaker in melee than a single class Bladesinger (assuming spells selected for that purpose). IF you are going to use bladesong, then you are going to be using single handed weapons and light armor, so the fighter levels are not doing much except robbing spell slots. If you are not going to use bladesong it is weaker than a single-class EK.
The problem with this build is you are losing a crapload of spell slots with those fighter levels. Those spells can more than close the gap in hit points and the extra ASI. When you get down to it, upcast False Life and d6 hit points is more total hps than d10 hit points.
If you really want the martial weapons I would turn this build upside down - Fighter 2, Bladesinger 6. You get action surge and a fighting style but only lose two caster levels and do much better damage.
Paladin 6/hexblade1 (or any hexblade dip on a charisma class).
I have seen this in play, it did not go well at all, part of that though is it was a PAM build and we did not find a magic Staff or Spear. He was often attacking without his hexblade weapon.
I think to do this well you need to have a generalist approach and not tie yourself down like that.
Even then, I don't really like this because you need a 13 strength for the multiclass, and then a 14 Dex to have a good AC in medium Armor or else you need a 15 Strength to wear heavy armor and not move slowly. So you can't dump strength at all, and unless you have a really good dexterity you need to invest quite a bit to be effective IME. This makes it so it is not much more of an investment just to give him a 16 strength anyway, at which point Hexblade is less attractive. Obviously it depends on your rolls. If you have one great roll (16+) and then multiple 12s and really want to play a Paladin, this becomes more attractive. Put your racial bonuses in Strength and Dex to get them to 13 and 14 and keep your natural Charisma .... but unless you really want to play a Paladin, I would be looking at less MAD classes like Rogue or Fighter.
Now IME Conquest Paladin -Undead Warlock 1 was Crazy Good.
Divine Soul xyz, Death Cleric 1
I have seen this. It is awesome. The Death Cleric necro cantrip feature rocks on a Wizard or Sorcerer. This is also great on an Eldritch Knight.
In the games we played it is generally Death Cleric 2 to get Harness Divine Power, and a weak turn undead.
Yes I have seen lots of Fighter 2/any caster builds. It is a tradeoff. I would say this is awash in general for most Wizards at high level. At low level a single class Wizard is probably better. You have action surge, but fewer spell slots.
Ideally you would want Heavy Armor, and Warcaster but that is difficult to cobble together while still being an effective caster as you are behind on the ASI tree already with the multiclass. You would want Warcaster from V.Human or Custom, but you can't do that if you start off as a fighter because you are not a caster. Then you need a high strength to keep up movement and playing levels as a character built to be a Wizard but with no/fewer spells is not easy. From levels 1-6 this is substantially behind a single class Wizard. At 7th level you catch back up and from there on it is probably about even.
Going Dexterity and starting as a Wizard is a much easier build but then you miss the heavy armor and you could do this with a race without doing a multiclass at all and keep all your slots but only lose out on action surge.
