Yes, but “fashion” also plays a role. Trident, B727 and Tu-154. TheTupolev has got lots of power (compared to the other two) and lots of mainwheels! “Look-a-likes”, but very different.
“Same specs. should produce similar designs”.
I also subscribe to this theory. Then someone pointed out – if you’ll pardon this military intrusion – the two Joint Strike Fighter designs. (Did the Boeing lose because it was so ugly?). Come to think of it: YF-22 and YF-23 were also quite different.;)