I agree near the end of the full some stops had short lines that's the only reason I stopped for Boo in Studios & Scrooge at Epcot as they were basically no wait
Epcot seems to have lot, but can be tricky seeing if the park is already open with day guests. Wide world of sports this year (2016) had a lot more characters in sports attire out too and those lines didn't look too bad (6-7 people maybe when I went by) so that could be a good area to get a few with shorter lines hopefully if they do that again. The villains in 2015 were one big stop where 2016 they were all spread out so lines wouldn't hopefully get as bad maybe, although when I went by a lot seemed to be on break.
However, characters actually aren't all the same in the half & full, spots might be but a lot of characters differed or switch out for breaks (at least in 2016 they did). You know the half ones from this year but some I remember changing between when I went by were
They half had Wreck it Ralph & Full had Chicken Little.
Oogie I saw in the half but Jack & Sally in the Full (not sure if they switched out).
Country Bears were in the full but at the half woody & Clarabelle were switching out in that spot. And the full Brer Rabbit & Bear were out somewhere too which I don't remember them in the half.
In the full we got Lumiere switching with Cogsworth and Sebastian switching with Ariel that were not part of the half.
Stitch & Lilo were in Tomorrowland in the full I think but on world drive maybe in the half if I remember right.
Oh & when leaving MK it was Peter Pan in the half but the parade sleeping beauty dragon in the full. (crazy lines of course both days)
I know Mary & Bert were the same and Golfing Goofy Donald were the same both days and that hot air balloon. Pirates were only the full this year unlike years past where they were in both as that big boat was gone.
So, basically my thing is if you see someone in the half you really want and the line isn't crazy stop cause they may or may not be there in the full. Maybe in the past they were more the same, but this year there were enough differences. I know you didn't ask but thought I'd share as far as I can remember