If I understand correctly, in TE, interaction with your heroes is actively used (quick army transfer, etc.).
At the same time, creatures can be freely taken from caravans.
In TE, coordinates are also used when approaching (to enhance skills), but it's not a given that the heroes will interact afterward.
And here, NCF creatures are not needed. The NCF idea completely destroys the racial skill of the Union – try to find the right, sworn creatures among a huge number of creatures...
Only the core is needed. There are no new creatures as such – there are only modified copies of old ones. Well, maybe you'll want to create a couple of specializations for summoning some specific new creatures or upgrading old ones to a new quality level (hello, Gelu from HoMM-3).
