This might be quite confusing honestly, seeing the ID's also checks for older versions.. Eg, I use v3Arcade for vB4, but it checks for a vBulletin 3.6 version of v3arcade.
https://vborg.vbsupport.ru/showthread.php?t=114012
Same with:
https://vborg.vbsupport.ru/showthread.php?t=192530
https://vborg.vbsupport.ru/showthread.php?t=151924
https://vborg.vbsupport.ru/showthread.php?t=117966
All 3.x vB versions. While I have vB4 versions installed.