Human wizard PC = just a human
Human wizard "Monster" = no longer human, different species
Mmk. Still gonna run it OG 5e. Here's my personal opinion and therefore it's the only thing that's correct and everybody else who doesn't agree is doing it wrong...
WBtW is an "adventure" book rather than a sourcebook. Sourcebooks (e.g. DMG, PHB, VGtM, MToF, and TCoE) contain guidelines, mechanics/RAW, additional content etc., which I see as the foundations to 5e mechanics and rules as opposed. Adventure books contain modules, which may be supplemented by mechanical alternatives that serve to compliment the titled adventure(s), modules. That posits any mechanically related content as categorically "guidelines" IMO, and thus DM discretionary. But that's the beauty of D&D and TTRPGs, right? As long as everyone at the (digital?) table is having fun!
I personally think the "counterspell standoff" is fun as a DM, and there's plenty of fun ways to nerf it without killing it. Like:
- Forcing a free perception roll to see if the PC can identify the enemy caster begin casting a spell, failing prohibits the PC from casting as they wouldn't have seen the casting commence in time to burn their reaction;
- Forcing the PC to make a free spell casting ability check, where failing would force a "roll off" between the casters spellcasting ability checks; or
- Placing other monsters that can counterspell the PC's counterspell... I even created a homebrew spell where a PC caster can spend their reaction to redirect a capped amount of damage from an enemy spell back at other enemies (check out below and feel free to criticize lol).
Y'all get the point. Just my take. Roll on everyone!