I don't see this as a addition that will give them a huge boost in rating because even if he as improved since his wwe days, he will still be perceive as a mid card talent. The biggest problem I had with Mundo during his wwe days was the lack of charisma the guy had, he was a great talent but had the charisma of a door knob. I don't know if he worked on this aspect of his game in LU because I don't get the show where I live and I'm not really going to seek it out on the internet but if I based this on his movie stuff, he's still have a lot of problem with that area of his game.
I think that he would fit perfectly in the x division because his style fit what that division is suppose to be and I would love to see him. Have match with guys like sonjay dutt and low ki just to name a few. As far as is girlfriend goes, she a good talent I assume since I not familiar with her at all but anytime they can get a indy talent for the knockout division, it's a good thing for them.