People keep arguing this point because it ISN'T obvious. Assume the following baseline:
Warlord Class
1d6 HD
Simple weapons, light armor.
2 skills, 2 saves
ASIs at 4,8,12,16,19.
Class feature: Action grant. You can spend your action to allow an ally with a level (or CR) of your level or lower to take any one action as a reaction.
Now, assuming that's it, no other class features, is it broken? It's obviously not the way a real class would be finalized, but with that framework and nothing else, it is OP?