i have to say that the age2 hero system is by far the hardest thing to come to grips with after playing age1.
let me start with the bit that is the same as age1
heroes are in the inn with a maximum base of 69 (at least the the maximum i've seen) helm heroes are the same as age1, mars and plate are good and the others are...meh

unlike age1, heroes have a maximum level of 100
so you really need to be sure you get a good base
to increase the attribute of your hero you have to upgrade gear
without gear heroes are just like age1

gear is upgraded in the workshop so unlike age1 you need to keep your workshop forever
just like the academy you research and the higher the workshop the higher the gear level can be

when i understand better i'll add another post but this is the basics


there are 13 bits of gear, upgrade of each gear basically gives you an extra point of attribute, the charm and ring add twice, each can be levelled to 10 with gear upgrades (no gems/stars) you can add 150points to the 100 that you get from levelling the hero
base 69 + level 100 + 15 level 10 gear = 319
applying gems to gear increase each gear addition but i'll post about that later

gear is researched once and works for all your heroes
the level of the hero impacts the available gear
hero must be at least a lvl 10 to gain the gear buff
the gear buff available 1/10 for each level, so a lvl 100 hero will get all available buff (150) but a lvl 60 hero would have a maximum of 6 for each gear (15 x 6 = 90)

the mount increases the speed of your hero, which also increases the speed of the troops they lead
when i was trying to understand how it worked i upgraded the mount
it has been difficult to get my attacks timed because of this and if i could do it again i would have left mount at 0
the same logic applies to mount so a lvl 100 hero gets maximum where lower heroes get less
spam waves are difficult to time (at least for me) so i usually turn it off