I agree with limits on multiplayer, as it’s only fair that way.
I don’t like the idea of limits when I’m playing for the enjoyment of me, myself, and I. I enjoy playing a challenging game, so I’m capturing as many monsters as I can and deciding from there which ones are going to be in my party for the long haul. However, if I wanted three Skullwraiths, or three Remus’, I wouldn’t be too happy if that were limited just for the sake of keeping the game challenging. The game can be challenging for anyone with any play style, though with the multitude of beautiful and powerful monsters in the game, people would really be cheating themselves if they stuck to a party of all Skullwraiths.
But if I wanted a super-boss-party of mega powerful monsters, that’s my prerogative. I downloaded the game, I should be able to pick how I want to play it without limitations. If I picked up a Pokemon game and I got a message saying, “They’re easy to catch, but you can’t have more than one Gible -> Gabite -> Garchomp on your game. Sorry, we want to make it challenging!”, I would be very peeved. I didn’t spend 40USD on a game to have it tell me that I can’t use more than one of my favourite. (That’s not my favourite, just for the record.) The game should be challenging, but a lot of the challenge should be raising those monsters to their maximum. Like training them in Pokemon, training them in Dragon Island, training them in this game. I don’t think it’s fair to take away the choices of each individual player when they’re just playing for themselves.
Multiplayer, however, should certainly have limitations, however you want to implement them; either by number of monsters brought in or level caps, etc. There should be limitations, to make it fair. But when I’m playing by myself, not competing with anyone? I don’t want my game to tell me that I can’t have more than one of my favourite monster.
There’s also bragging rights. When you have a party of one type (sticking with Skullwraiths, for argument’s sake), you might be able to sweep the game, sure. And then you can boast and puff out your chest and tell us all how quickly you beat the game. But the people with more balanced parties will discover more of the game’s out-of-the-way secrets, will explore every corner of the map. They’ll get to know the monsters, pick favourites, and learn that just because a monster isn’t pretty, doesn’t mean it’s not very good to have on your team. They’ll be the people that give out advice to new players and, if they’re active at the forums, will be respected and well liked, and will be known for their knowledge of the game. Then those that swept the game in a week, with a single type of monster, will quietly seethe behind their computers because suddenly no one wants to hear about what they did. Everyone will want tips from the people who beat the game with a myriad of different monsters. I think the single-type-sweep would be very unpopular, and would gain that negative reputation quickly. No one would want to play like that.
And then there are the people who will play like that, but won’t be an active member of forums. They’ll join, ask a question, receive the answer, and then not show back up until they get stuck again. When people like that (with a party of 12 Skullwraiths) go here to find answers to their problems in the game, they won’t find any. No one that frequents these forums will really play like that, because of the previous paragraph. I’ve seen it happen before - fad grinding, I called it. It was popular for a brief moment and then a quick bit of wind blew that candle out very quickly. When asked about it, people will never give a definitive answer, because they eventually saw that they weren’t getting the most out of their game. Anyhow, the people that came here seeking answers will find none, and one of two things will happen. They’ll rework their team/start a new game, or will walk away from the game. Remember, no matter how large the fanbase is, no matter how much they love the game, there will always be people who won’t like it. Can’t please everyone.
I just don’t see the Skullwraith example being a large enough problem that limits would need to be implemented and enforced. If it doesn’t effect the way you play your single-player game, doesn’t effect the new updates that developers have in the works, it shouldn’t be an issue. Multiplayer limitations, however, should certainly be implemented. It should be a challenge, but not impossible to defeat other players.