Generals really depend. I tend to pursue blitz strats and these use and perhaps abuse the BG's power. Those BGs regenerate provided the character is not killed.

The game tends to try to balance the number of generals and cities so you get more breeding if you have only a few.

I like to take Athens and the prebuilt academy there makes for good studying ground for new generals. They will get some nice traits and head off for the front. I also transfer bad ancillaries onto deadbeats and use them as suicide cav force, often in my armies (not commanding). They can rally troops and also charge protected missile units, often taking them out at the cost of their own lives.