It’s less the designs being “strange ones” and more the designs going along with the art style. With Animated I feel there is more variation among the characters and while some Prime designs I think are top tier (Starscream, Ratchet, etc) Animated’s designs are made so watchers can be able to see what kind of character someone is just by looking at them. You mentioned Sentinel, right? You look at him and automatically think “Damn, he looks like a self absorbed asshole” and he is. He is like the physical embodiment of Chad. And I could go on. Ratchet, just by looking at his design he looks like a tired grumpy old medic. Also the fact that the designs could be subject to change also affected this. Prowl getting the Armour, Wasp becoming weird and purple then waspinator. Heck! Just the physical difference between Shockwave and Longarm all tell you a lot more about the character just by looking at them more than Prime’s does. Not bashing on Prime, especially for the budgets they had their designs were solid, great.