Yes, I understand I can have them auto join a certain fleet, but sometimes I'd rather have the ships stay put for defense reasons and assign them to a fleet later.  Ideally I would love to just select the units and just R click on the fleet leader icon so they can join the fleet.  I swear it worked for me one time, but I cant get it to work again.  

Well I dont think it  has anything to do with auto join, because I'm not tying to auto join.  I'm saying if I already have a fleet set up and I just want to randomly add a few more ships to it, I cant.  Well I can but I'm trying to figure out if there is an easier way.  The way I have to do it now is select my fleet, then shift click all the units i want to add to it, then hit create fleet again.  I also tried where, if i have a fleet in a gravity well and there are additional units in the same gravity well, but not in the fleet,  I'll just click drag and drop over all the units and click create fleet, but sometimes it will select a new ship as the fleet leader, and I dont want to tab and sub select my capital ship every time I do that because it takes up time.

that may work against ai or some friends of yours. but if you play this game at a macrolevel (not zooming in on planets, autoabilities turned all on and so on) you will find fleets very very handy for your strategies. they just allow to group up big fleets way faster. even when youre in battle zoomed in, you will find it very handy that you just press 0 (or whatever shortcut you chose) for your forgeworlds and spam ships wich will automatically search their way to the individual fleets you rallypointed earlier and then join in if arrived. this is a very very powerfull thing i guess. but im not as pro as some dudes here, so this is not THE truth, but "my truth" pls some 1337-g4m3r2 opinion on this!

greets from still-rainy-germany