I just wanted to add that leaning a PA28 is a lot harder than a C172 which I've done a lot thanks to 40 hours of flying in Arizona. The friction on the lever, it's design, feel and the movement range makes the task practically impossible in some older PA-28 aircraft. You have to use two handles effectively. One hand as a safety guard against too much movement of the lever by the other hand. Otherwise it'll be oops, !
This has me curious.
Why?
Are yo saying that a cherokee is harder to fly than a skyhawk?
The mixture is harder to adjust?
The throttle is harder to manipulate?
Place your hand
on the throttle quadrant, rather than holding your hand
over the mixture or throttle control, and manipulate the lever using the base of the lever, not the top...and you won't have any problems.