No, this is incomplete. So I’ll give a more full version since people tend to only read things that aren’t pinned and are thrust right underneath their faces.
Firstly, as much as I hate this kind of behavior to some degree, spam for friends until you unlock all the slots that are acquirable through adding friends, I believe that number is 8 which is actually a pretty good number (if it is 7 that’s also workable).
As a general rule of thumb you will have 5 war/command heroes that you will use as that’s your maximum capacity (how you stat is up to you). Focus on equipment with war and war stat as it’s optimal, equipment with both stats are also OK. Do this step for 5 different heroes who initially begin with higher war or command stat as that wastes the least stat points.
For the other three (or two) slots, get one tech hero, by this I mean stat up the tech stat only and acquire equipment with as much tech as possible. The rest can go to build heroes which follow a similar principle just with tech substituted by build.