As for your seeing three heads at rest, this is the interpretation: For the three heads at rest, see the comments on 2 Esd 11.4. Here is an alternative model for this verse:

• “You saw the eagle had three heads, all relaxed. Here is what that means:….

Quoted with permission from Bullard, Roger A. and Hatton, Howard A. A Handbook on 1-2 Esdras. (UBS Helps for Translators). Miami: UBS, 2019. For this and other handbooks for translators see here.