5 man clan war!

I think it'd be cool I see nothing wrong with it.

5 man clan wars are a leeway to MISTMATCHES. It also means that not everyone will be able to attack their preferred targets. I don't like this idea

No way, there is no meaning to clan war if your clan doesnot have 10 members at least

No reason not to put it in, if people don't think it's worth then they just shouldn't do it at all, you have the option for a 10v10 you know, I just think that it's a great chance to give a lot of these new players some early on experience, because not all these clans want low levels. Also it's sometimes a lot more fun to just play with a small group, it's an esoteric feature with no harm in it.

I think it would be to easy to get perfect wars

I don't agree because, 80% of 5v5 wars will result as draw wars. That is first, second, clans will easy farm xp..

Well first off in the case of a draw, the destruction rate should be a tie breaker, if not then some other stat should maybe time?
Secondly, the 5 man clan wars would have less loot and everyone would only have one attack and in addition to the fact that it's easy war stats, lessen the amount of xp given and perhaps not even put it on the war log, or just give it a separate section. There's no reason not to allow it either it's a great way for smaller clans to show that they have skill and they might be worth something, perfect for people trying to build up a clan. War wins are a rest way to advertise your clan, even if a 5v5 is under a separate section.