Seems like they needed to test a few things for non-tactic servers. The morale is added up to a total value so you can keep everyone in the same group... (i.e, for tactical servers, you make 2 separate groups both consisting of 1 hero with x army | in non tactics, you can have in one group, 2 heroes with 2x army. The attack in both cases are the same.)

Quote ibizafree:

must be in just one army?

yes, but here is no disadvantage to this... well maybe some minor ones..

Quote ibizafree:

In this case its not usefull send more than 370 of each arches troops ?

if you have more than 1 hero, then its fine [considering it does not exceed the combination of morale of both heroes]

OK, lets say (just imagine) that one hero with master leadership allows 100 archers to attack.

now, on tactical servers, if you want 500 archers to attack, you need 5 groups, each with 1 hero and 100 archers.

now, on non-tactic servers, if you want 500 archers to attack, you need 1 group with 5 heroes and 500 archers.

Do you get it?

Also, hero's skills work in a different way. in battle, there are 1 minute rounds. in each round, a hero is randomly assigned to a random unit. That unit will get all of the hero bonus (like they normally would if that hero was in a group with the selected group).