After putting together the checklist, I realised why the Commander/Scout Optimus and Megatron have removeable accessories (the jetpack on Optimus and the Tank on the back of Megatron) - it's so that when they are removed, they are closer in size/bulk/mass to Legion/Legends figures for the Action Sets. Bumblebee and Starscream are Legion/Legends figures (and Roller probably is as well), but I seeing Optimus and Megatron included in wave 2 had me thinking they were all Commander/Scout figures. But later noticing that the Bumblebee was just a redeco of the Legion/Legends wave 1 Bumblebee, it made me look at it from the opposite angle... how was the Commander/Scout figures being included where it looked to be 'Legion + playset' as the makeup of this size-class.

So I decided to add this note on the Checklist:
Bumblebee & Starscream are Legion/Legends size, while Optimus & Megatron are Commander/Scout size but stripped of their accessories, making them closer to Legion/Legends size when on their own.