I agree with you for not taking the shot. Never shoot unless you can 100% identify your target. This time of year gets tough calling. Many of the critters left have already been called before and even shot at, therefore they are very weary. You’ll also find if you hunt a lot of fields fox will often hang up 200 yards out and just sit down and watch, listen and smell. Many times never come any closer. All you can do is throw some different sounds out there and hope one of them triggers them to respond. I like using Foxpro’s Bay Bee cottontail as a coaxer. Sometimes a simple bulb squeaker works for me. Vole squeaks is another good one. Play softly. If they bark, usually it’s because they don’t like something and it’s a warning to other fox. Sorta like when a stranger comes in your yard and your dog barks at them. Coyotes will do the same thing, from my experience, when a K9 barks it’s game over..... they won. Try using Red fox Rally if you have a foxpro and bark back. It may get it to move enough for an identification and even a shot. Most likely with two sets of eyes this time of the year is a mating pair running together.
Good luck, I hope this helps