GMforPowergamers
Legend
I'm sorry, but if hybrids like the mystic theurge were supposed to work like that, then we wouldn't have gotten the Eldrtich Knight or Arcane Trickster subclasses - because that's all they are. Wizard - Fighter and Wizard - Rogue prestige classes turned into 5e subclasses. By your logic, you shouldn't need a subclass for these combinations - just go one level fighter/rogue, one level wizard, repeat.
5e multiclassing isn't designed to handle hybrid combinations very well. Not with how level progression and the tiers of play work. Especailly with non-caster characters - no stacking of extra attacks is a huge loss, and a (for example) Paladin 6/Fighter 5 will be distinctly weaker than their single class counterparts at the same character level - fighter would have third attack, paladin Improved Smite, a fighter / paladin gets nothing. Casters have a similiar issue - their level 3, 6, and 9 spell lists are huge jumps in power. A fireball cast as a level 9 spell is no match for a meteor swarm. A chromatic sphere cast as a level 6 spell has nothing on disintegrate. Even something as casting flaming sphere as a level 3 spell is embarrassing compared to casting a fireball, and that's just a 1 level difference.
There's some stuff you can do well with multiclass rules. Hybrid leveling? Not one of them.
I agree a lot but there is a lot of disagreement in this thread. I think that multi classing spell casters was a huge issue in 3e and they fixed a lot of it. However there are still some patches to be made.
a fighter level 14 has 3 attacks and some kind of cool features (half of them in the second half of the class)
a wizard level 14 has 7th level spell slots and 7th level spells known is more powerful and versatile then the fighter. (a problem of class balance)
a fighter 7/wizard 7 is not as versatile or powerful as the wizard, but is more versatile then the fighter, but less powerful...
this is an issue, and one eldritch knight kind of fixes, in exchange of your subclass you would get 2 more spell caster levels out of that.
my problem is that high level powers are better then low level ones. Once you comet to a multi class you give up ALOT of cool features there is no reason why they can't have a PC fix that like they did 3e...