- Neutral creatures in Heroes 3

I disagree. For example, the Black Dragon horde. You want to join them, but you might not have enough army strength for 3-4 months. And they will demand so much money that you definitely won't be able to collect it in the first few weeks.

How many is a horde? (It varies everywhere)
This has happened, of course, but I played without thieves, and about 30 joined without any costs, just like that and without (as well as with) diplomacy. True, it didn't work every time when replaying.

I'll repeat what many think - snipers are the most useful.

In my opinion, the advantage of neutral creatures lies precisely in their limited availability.

Best regards, Draco