If you're sweating while you hike, you should be wearing less while you're in motion. One layer may be enough. Other options to reduce sweating include opening the shirt, pushing your sleeves up, wearing less insulation on your head.

I assume that you carry a rain jacket and an extra insulating layer or two (as we do up here in the PNW). That will keep you from getting chilled when you're stopped. The jacket you mention won't keep you dry if it's raining!

I don't understand why you'd want a separate jacket from what you already should be carrying.