Hi Ferb (and welcome),
Always at least 3 generals, and up to 5 in the most professional armies. Heroes from 3-6 ish, depending on my perception of how important heroic leadership was in the army. More in armies with a lot of warbands.
Usually the most common troop type x the maximum number of elements comes to around 100 points or thereabouts.
A good place to start is with a similar list to the one you are building and take it from there! Drop me a line at my address in the shop and I'll give input as you go along.