So, for the last few months I was hard farming General Grievous out of fleet shipments, (and let's not discuss here how dumb that actually was of me), point being: I got to within 5 shards of unlocking him, a single purchase away - and then he didn't drop in the fleet shipments for me for TWO MONTHS.
But - it gets better. When GG finally did drop in the fleet shipments it was only after I'd finally gotten tired of waiting and spent the last 400 tokens I had otherwise been saving for when he did show up. Joke was on me.
I guess my point behind that long, pathetic tale is: it happens. Oh, and don't waste your time farming GG - he's really just awful.