I own both. Keeping one would be a opinion on preference of the style of gameplay desired.
Lotr is a great story based game. I don’t always have long ball times but when I do, it feels good to get deep into the rules. The music, call outs, modes etc make me love this game.
Mm - great game, but kind of shallow rules. Call outs are great, trying to get all shots in a multiballs can be challenging. Not super long ball times. Fun to bang around on.
If you want a casual game, mm. If you want a story/rule game lotr.