That sounds like more work for the GM. To use the systems I'm familiar with, I vastly prefer 5E D&D, since I can just say "Build characters with 27 Point Buy, PHB Standard for HP, and no SCAG. Run UA or homebrew by me before using it, but official material is okay. Starting at level 10," and have a reasonably well-balanced party, whereas in 3.5... Well, if all I did was say "32 Point Buy, HP is max at level one then average rounded up every level thereafter. Only books are Core and Complete. Starting at level 10," I can end up with a Monk who's got decent punches, a martial multiclass that can do 1,500+ damage in one turn, a Cleric who's nearly his match in close combat (and has full casting besides), and a Rogue who's just really good at disarming traps.

I'm not saying it's impossible-but I am saying it's not generally desirable. It's better to have the characters be balanced (by whatever metric of balance you want to use) by the system, rather than forcing more work on the GM.