AbdulAlhazred
Legend
That is indeed where it would be discussed. However, those guidelines don't talk about the appropriateness of using minions against PCs of a given level. Sure, the level 1 wizard versus the level 30 minion is the most extreme example, but what about the level 1 wizard versus the level 5 minion? There's nothing in the guidelines to suggest that you shouldn't do that.
Ahhhh, Grasshopper

I realize the DMG never really comes out and says "hey, minionize lower level monsters into higher level minions" but Monster creation is only loose guidelines in terms of WHAT you build or why. Making such a conversion is quite easy in general.