Hi,
I agree with you, the matchup Isen vs rohan is really hard right now. I would also go for wargs in the eg, since both scouts and wildmen are pretty useless vs cav. Part of the problem is that the howl ablity of the wargs doesn't work atm, since it only buffs their speed, not their damage. If that was fixed it could improve Isen's chances quite a bit.
But other than that I can't really help you unfortunately.
Best regardes,
Seleukos