It’s definitely a try it and see thing. You’re degrading the local side’s performance by a bit when you peel one of the antennas off. Having said this, it’s been a bit of a common trick (with varying levels of success, mind) to do this sort of thing to create a WDS spanned network between buildings where you have enough “juice” on the local leg to allow everything to work and the two or more AP’s in the WDS use the directionals.