sounds interesting! it is hard to decide which engine is better for a certain project, the best to make some tests in both, which is a bit time consuming in the beginning, but will be much faster to complete the final game.
now I approximately know 3dgs limits, I'll have to test esetnhel with my pathfinder by writing custom classes for it (probably independent of the terrain areas because of their streaming in/out).
I found that 2d system, unfortunately it is limited, and was used only in the past, after navmesh it was abandoned (and I need to handle a few building levels not only one).