With all the new enemies, their resistances and all the new specialized weapons to defeat them there is no way to build a super squad capable of beating any situation. Therefore i think being able to re-equip in the dropship once you find out what you're fighting would be a great mechanic, i believe there was something similar in the original xcoms. If this is not possible how about adding a mechanic where you can scout a ufo landing/crashsite to get a rough enemy comp before you send in your squad.