Ok so I wrote up a whole post on this, but apparently it was too long so I had to cut quite a bit of stuff out.
With the popularity of games such as DOTA and League of Legends, it was actually kind of surprising to see something similar make its way into FFXIV. The thought of being able to pit your special minion against other minions was a great idea. In my opinion, I feel like it could have been done differently though.
If I was really going for a stretch here, I would compare the current Verminion more to Starcraft than I would the other games I listed, which may be what it was going for. Now don't get me wrong, Starcraft is a great game, but I feel like if Verminion took the MOBA approach, it would be way more fun, if not more competitive.
I think it would be way more fun to have players be able to choose one minion. Each minion would have a set of about 3-4 different abilities, and have different game modes like 3v3, 5v5, or maybe even 2v2v2v2.