true & true.
Some are simply a judgement call. "saugeye"
Sauger don't get as big as walleye so generally speaking your saugers are smaller. but you can catch an odd sauger that dwarfs your "keeper" walleyes for the day too.
Sauger will have spotted webbing on the dorsal fins & no white patch on the lower tail fin corner.
Saugeye... well they are tough & the DNR doesn't recognize them when counting limits. It's one or the other (walleye or sauger) and they are going to call it in the favor of the fine they would like to collect from you