It's an uneven equation due to where the designs come from. Most Legends toys are simplified versions of already simple toy designs (Cybertron), or new designs made with the limitations in parts numbers of the Legends class in mind. Movie Legends have the difficult task of trying to replicate very complex designs with a very limited number of parts.
Cyberverse Commanders are sort of like the old Basic price point, above regular Legends (or Legion, in this case), but below Scouts. The intent of the Cyberverse branding is to have a new play pattern where all similarly-sized are in relative scale to each other (with playsets!), rather than just have a price point of small, cheap toys. Also, encourages collecting with series numbering.
The Human Alliance basics are basically the Scouts of this line in terms of complexity.
As for why the Scout price was moved up, larger Legends (essentially) were moved to the Scout price, and why Deluxe and Voyager class toys are smaller than usual, it's probably due to plastic price rises. The MechTech weapons aren't so large that they steal that much space on a sprue away from the toys.