I hope this is not really a widespread problem... If it seems to be, a lot of pilots are flying with the wrong other pilot. The pilot flying should be demonstrating enough skill, that another pilot would not think to "take" and control. More experienced right seat pilots should be making allowance, and not getting all excited about perfect flying - certainly not "taking over" to fix it, unless it's life threatening, which takes us back to the first point.
Aside from the aforementioned isolated events, where I had to quickly take control to prevent a crash, 'cause I'd left it too late to talk the pilot flying through a fix for the situation, I have never felt that any need to "share" the flying was needed, other than entirely by happy comradery with the other pilot.
If two very new pilots are doing this to each other - give your heads a shake, and stop it!
This should not be ever allowed to get to the "problem" stage.