big enemies physics problems

[Nahuel]

well, I have noticed that the enemies with bbox sizes bigger than to the quake size of the player (-16 -16 -24,16 16 32), have a lot of trouble getting down-high stairs and often get stuck on the map.the solution would be simply to resize them to the player's size at max. but that's not what I want.. I'm using q3bsp so q1bsp hulls are not a problem. There is some way to make the big bboxes in enemies work with the same physics for smaller bboxes (like player size for example) . I am working in darkplaces if that requires engine changes, what are the steps to follow?
Thank you very much