In principle, this modification cannot be installed on top of Epic War Age.
Added 2 minutes later
Returning to the frequently asked question:
Is the EWA 2.6.2 mod compatible with the new heroes mod NHF0.85?
/topic/9337/
At the moment, it is compatible if you first process the map with the NHF patcher; however, it will only work correctly in multiplayer maps. NHF does not work in campaigns; as for scenarios, surprisingly, it works in some (it all depends on the map). Also, the EWA launcher automatically disables EE and MegaAI if NHF is enabled.