[Gatts]

Well, I have done some research on this:

Normal + Easy: 101% ~199% of leadership -> You don't have control over the unit, but the unit may not attack you (I do believe that tha chance of attacking you could be slighter higher on Normal) and has chance of attacking enemy only (again - this chance may be smaller on normal) - otherwise the unit will only move, defend

Normal + Easy 200% + -> The unit goas RAGE -> will attak you (on normal only you, on easy anyone one)

Hard : 101% ~ 199% -> RAGE - will attack anyone
Hard: 200% + will attack only you

Impossible: 101% -> Rage -> Will attack only you

(I have not double checked it - as it is not so easy to move your numbers of units in combat... maybe using hex editor could help , but using hex editor mostly prevents the game of "knowing" / "reacting" on the changed number... so again no accuracy is gained)

Anyway here is what I did:
My Leadership could hold 11 horseman.
Impossible: I raised them using sacrifice to 12 -> their info bar changed in RED - my army considered this unit as enemy, real enemy considers this unit as friend

Hard: again 12 Horseman, again red info bar -> but this time the horsemen attack the dragon, and the dragon attaks back horsemen... I can still attack horseman

Normal: 12, 18 Horseman - info bar is still blue... the info window shows the "red" crown - but enemy considers this unit purely fiend, and my units still consider it like friend... 23 horseman - bar goes red...

Easy: very similar as Normal... I only have the feeling that now the unit may behave much more "useful" - may attack enemy more often, and less just move around... also I never experienced that it attacks my other units...(not when it was below 200% of leadership)