I've only had the one, so I dont think i'm qualified to say . . . . .
That was our biggest concern when I got her, that she would get too hot, and feck off on a line for miles, taking the rest of the dogs with her. I put a MASSIVE amount of time into her, which I had the luxury of doing as when she was a put , co-incided with our rearing and releasing of pheasants etc, so she just came about the shoot with me all day every day (helps she fits on the quad). I also never took her out with another dog until she was around 8 months, making sure she was totally me focused. It seems to have work