It's uncertain whether or not Jenny or Doctor could take him alone (I'd lean toward the slightly pessimistic simply because Thanos is so crafty and intelligent to go along with his power), but together they would undoubtedly hold the edge, especially when Apollo/Jack/Angie could annoy him and play hit & run while the big hitters did their things.
Take either one of the Big 2 out and it would be a good fight. I'd lean toward the Authority, but would take Thanos for the majority if he managed to isolate whichever of the Big 2 wasn't eliminated from the roster.