dodge vs. plymouth???

On 70`s cars I see some trend: Plymouths=shorter wheelbase and less content when compared to Dodges, for example Cuda vs Challenger, Duster vs Swinger, which it translates to lighter cars, providing an advantage performance wise.
In the case of the Duster, Dodge was behind on sales, which resulted on its counter attack, not as successful though, with the Demon and later Dart sport (sad story the one of that evil character)
I am a Plymouth man, one of my favorites, that plain jane car which was a great success, the roadrunner, of course besides the cartoon character factor, its entry versions were very low optioned: bench seat, rubber floor, manual trans, but with great guts coming out from a BB engine.