[tinkthank]

PS. I see you posted in the meantime.

You have a new argument.
Yes: No-brainers are bad.
A sage is not, however, always a no-brainer, although getting about 5-6 sages asap is almost always good. Sages are better at research than any national mage, period (although I am not sure about the Philosopher); that is their raison d'etre. But they can't do much of anything else. Having them boosts your research very quickly, if you have the money for the lab and for recruiting them. But they are certainly not no-brainers over other commanders; I have never played a game where I stop making my own commanders because I find sages.
Still, if everybody thinks that he who finds sages in MP will likely beat others, then I would prefer that their RP bonus be reduced from 4 to 3.