some guys get gyno from even slight estrogen increase.. some guys don't get gyno no matter what. some guys get gyno from even looking at a bottle of gear lol (being facetious but you get my point)
its all about being prepared for anything.
there is also prolactin gyno that you can get from running tren. this can be taken care of by running caber/dostinex.
i feel sorry for those who are extremely gyno prone, they will sometimes end up having to do surgery to get the gland removed.. while other dudes run all the gear they want with no AI and never have anything happen to them.