Not sure if they’ve changed the design of rainlegs, but the straps round the back of your legs used to wick the water, or it ran along them, therefore wetting the back of your shorts.
How about my favourite Sprayway all day rainpants? Stretchy, not sweaty, but not bike specific, so you’ll need trouser clips at the ankles! I used them all the time for cycling when I had no choice but to be out in the rain, and loved them.