Well, it is quite meaningless to begin a fandom "war", at least it is meaningless to me. Everyone may have a different preference, and it has generally no development on anything at all. It is good to see everyone has a preference, but it does not need to have a crash or "war" between them.
To me, it will be "IM@S > LoveLive >> Aikatsu! > Wake-Up Girls". IM@S is always the top to me, even counting all other anime or games. Lovelive is also good, but it is sad to see those girls are too similar. And the story of LL anime is somehow too common as other anime.
Just some facts, a few month ago, around November, there was a informal survey about the "war" in the Japan, and the result was as follows:
LoveLive > Wake-Up Girls > IM@S ~ Aikatsu
After the success of IM@S Movie, the popularity of IM@S was boosted up again. And it was sad that there are many negative comments about WUG. The result now is as follows:
IM@S ~ Lovelive > Aikatsu >> Wake-Up Girls