The direct sound itself should be the about same SPL. Complex dispersion patterns of real world sources and room reflections will skew things.
I dunno.. if they are the same distance they should be the same volume. They are pointed at different areas. So they won't be the same exact sound but they should be the same volume.. I dunno though.
Without fear of repeating myself : Equal distance will give you in phase signals but if directionnal mics point at different directions, they may not have the same volume comming from the bass drum.. You should get more balanced results with omni mics..