The only adapting OKW is going to do is go for Puma every game because you are simply not going to counter allied light tank rushes with medtruck units and a 50 range AT gun.
Ostheer doesn´t need puma to kill Stuart. They have pfaust + Pak + 222. OKW have Raken + pfaust + HT or Puma or Luch.
Ostheer = pak (high range) + 4men gren pfaust + low damage output 222
OKW = raken (low range but camo) + 5men volk pfasut + high damage output Luch or Puma.
Something everyone seems to forget is OKW is getting HMG34 from T1 and HMG42 from 2 doctrines. This means: easy lockdown flanks, better territory control, forcing opponent to flank more etc... What OKW loses in AT department OKW wins in AI department.
You'll need less volks to control your territory while still keeping OKW push ability with Sturm and Kubel.
I have some mitigated feeling about OKW getting stock HMG and losing shrecks, in a way OKW is losing its identity. But since this identity is full of craps and spam, it is definitively better to change it. Same if this means having something bit more similar than Ostheer, both Faction remains vastly different.