If you are sending for example say 10 expeditions at 12.00 with a return time of 14:00 you then have to allow for speedy returns and delayed returns after the third wave in an ideal world the return time would be 18:00 but the return time in reality could be anywhere between 17:30 and 20:00. (As you know UNI 1 is not a healthy place to leave a fleet sitting)
There is nothing with General and Collector having Pathfinfers what I disagree with the is ability of a class other than Explorer being allowed to build them. If they find them or switch classes then that's not a problem.
But if you open them to General you would also have to allow Collector the same,,, so then the result would be that Explorer lose their unique class specific ship. So what would Explorers get in return ?