don't know what just dance games u were looking at, but I've downloaded them twice.
Just Dance 4 - 22 x .app files, largest single .app file is just under 2GB (Title ID: 000500001010F000)
Just Dance 2014 - 17 x .app files, largest single .app file is just over 3GB (Title ID: 0005000010143F00)
Just Dance 2015 - 19 x .app files, largest single .app file is just under 2GB (Title ID: 0005000010176F00)
Just Dance 2016 - 24 x .app files, largest single .app file is just under 2GB (Title ID: 00050000101B9800)
Just Dance 2017 - 24 x .app files, largest single .app file is just under 2GB (Title ID: 00050000101EAA00)
Just Dance Disney Party 2 - 23 x .app files, largest single .app file is just under 500MB
(game not on NUS, WUD extracted) (Title ID: 000500001016C800)
Just Dance Kids 2014 - 23 x .app files, largest single .app file is just over 500MB (Title ID: 0005000010145B00)
I have installed every single EUR/PAL game, just over 150 games to USB and non of the .app files was over 4GB.
Unless the files on the NUS server has changed to combat wupinstaller method by having one or two .app files larger than 4GB, this way you can't copy larger files to FAT32 SD CARD.