The term “out gunned” applies to optics just as much as the rifle. Ever see an expensive battle rifle or dmr with a shitty optic? It’s hard to look at.
Not ideal at all imo. Just leave it on one of the two. In a real combat scenario like a possible hasty ambush or coming in contact and having to instantly go into fire and movement, you're not going to have time to get to cover, swap, and then be able to locate their new position and gain fire superiority because they'll already have it. Also, swaping back and forth like that means it's not dummy corded to you which means you'll probably lose it at some point.
At 10-20 yards this might be fine but this will cause an "image"shift when looking through your sights. You dont "look through" a thermal. A thermal is basically like a video camera. It reproduces what it sees as visible light on a screen for us. What u see on said screen could easily be sqwed. And mm on the shooters end =feet down range.
It has to be collated first. Since you’re not actually looking at the target, youre looking at an LED screen that shows representation of the target, your zero will be off. Dirty civilian does a great video on this