Kevin
You're not swapping your attributes around. Managers who adopt this strategy only use the different CDs to maximise research for this season.
At the end of the season they reset their cars for next season so as to have the CD strength in only one attribute. Of course, when you adopt this strategy only the CD strength is important, weakness is irrelevant. The only CD that has to have a "good" weakness is the one you use to reset.
But as for the sugestion I'm not sure I agree. Everyone has a limit of 5 CDs so which attribute you have to sacrifice is another management decision you have to make. Different managers will presumably adopt differing research and development strategies.
With a limit of 5 CDs, those who can afford it will swap CDs in and out of their multiple accounts to optimise research.
I disagree with you. I should be given the tools and opportunity to make proper choices and not handicapped. That doesn't make it any less a management game.
I shouldn't be 'forced' to sacrifice, I should 'chose' to sacrifice. That's better management imo.