Mathews TRX7 and TRX38

I have had the 7 for a few years now recently I acquired a 38 which as the same cam and module setup. The valley on the 38 is virtually none existent towards the 7.
apart from the shorter ATA I don’t know why it is so maybe a member can shed some light on the subject.
I intended using the bows for different types of archery but didn’t expect a noticeable difference Or learning curve.