Just observing that the fighter can be burned to the ground in the name of 'simplicity' and that's apparently fine. One spell gets simplified and that's a major issue.
I'm not even against expending command's utility, but parity and consistency would be nice.
Well there's a couple different ways you can set it up:
1. Wizard and fighter both get hammers, wizard also gets a Swiss army knife (both classes get raw power, wizard also gets flexibility).
2. Wizard and fighter both get hammers, no Swiss army knives for anyone (both classes get raw power, wizard flexibility gets removed).
3. Wizards and fighters both get hammers and Swiss army knives (both classes get both raw power and flexibility).
4. Wizards get Swiss army knives, fighters get hammers (wizards get flexibility, wizards get raw power).
5. Wizards and fighters both get Swiss army knives (nobody gets raw power, everyone gets flexibility).
6. Wizards get sledgehammers and sonic screwdrivers, fighters get hammers (go home 3.5e, you're drunk).
1. Is more or less what we get in 5e. It's not ideal since it gives casters an obvious edge but I can work around this problem by playing ball with any harebrained schemes fighters have, make their superior HPs matter, give them sweet magic items, play at mostly lower levels, really work at attrition so the casters never have enough spell slots, encourage half casters over casters, etc. It's not ideal but I can make it work.
2. The 4e solution. There is a reason there was a big backlash against this solution.
3. Your solution. I'm fine with this for the most part, but it just feels more high magic than I like (but then so is 5e and 5.5e seems even more high magic) but would be great for a more mythical heroes game.
4. My solution. Smack casters enough with the nerf bat so that in a straight up fight or a DPS contest the fighter comes up obviously on top. Casters have to be cunning rat-bastards with spells like Command or rely on out of combat utility to compete with fighters. I like this. This closest I've seen to this in a D&D-ish game is d20 Conan, although lower level TSR-D&D also did it well enough since low level wizards were so damn squishy that it took longer for their quadratic curve to start getting them high above fighters.
5. This is not something D&D has ever tried to do. It's something I'm puttering with for a game I'm trying to write in which the PCs are fairy tale heroes faced with problems that they simply can't overcome with raw power (so kids vs. a giant) so they have to rely on their wits, collecting favors, and bits of magic and skill to come out on top. A lot of the skills would be things like "smell lies: you always know when someone is lying" so the "mundane" skills would have the potency that you often get in fairy tales.
6. Blech.