It is my personal opinion that Yoshi and Wario of more sub-franchises. Donkey Kong, however, is its own franchise, that nowadays only overlaps with Mario in the occasional crossover and Mario Kart.
Ask yourself this, would you call Donkey Kong a "Mario" character or a "Donkey Kong" character. Now ask yourself whether you would call Yoshi a "Mario" character, or a "Yoshi" character. Is Wario a "Mario" character, or a "Wario" character?
It doesn't help that Mario appears in all the Yoshi games, and Baby Mario made an appearance in Mario & Luigi: Partners in Time.
Plus, you could argue that Yoshi and Wario do deserve a wiki.
Its a bit more convoluted, Donkey Kong is the first game and Mario spun-off and became the more recognizable part and all DK was known as the game that launched Mario. When DKC came out it set itself apart from Mario and was able to be seen as a separate brand from Mario, of course DK64 failed to get people on fire like DKC did and after that Rare was sold and Nintendo tried to keep the DK franchise alive but they were all failed tries (hey I liked them!), so for the past decade DK has been seen mostly as just "part of Mario" instead of its own brand. DKCR aims to change this but who knows how successful it'll be. The point is while Mario spun-off DK it became the bigger name and while DK has tried to brand itself different its still part of the "marioverse" so to speak.
Now Yoshi and Wario are another story. Yoshi is the less successful of the three, however I definitely consider his game a 'brand' in a similar vein to DK. Yoshi's Island was the game that spun him off and even though it was called "Super Mario" for name recognition it is not considered a Mario game, the 25th anniversary of SMB pretty much cemented the fact. The success of Yoshi's Island made him his own 'franchise' headlining Yoshi's Story with no Mario at all and established Shy Guys as his rogues canonizing SMB USA in the process. Sadly Yoshi hasn't been wildly successful so we haven't been able to see a lot of the Yoshi brand separate from Mario though theres plenty of Yoshi games, don't forget in the original SSB he also got his own icon and didn't have to share with Mario.
Now Wario is a different story, his first appearance was in Mario Land 2 and spun-off with Mario Land 3 which is basically just a Wario game with with Mario slapped in the title to guarantee the game would sell like SMW in Yoshi's Island in case the Wario/Yoshi brands weren't big enough. Since then Wario has been its own entity pretty much only crossovering in party games, in some ways its been better than DK in setting its own name separate from Mario, especially with the Warioware series. Super Princess Peach and Luigi's Mansion could be seen as trying to launch them as their own brand which failed.
Anyways the original point was Wario is as much of a separate entity from Mario as DK and even Yoshi is. Both Yoshi and Mario have mostly been carried by the Mario franchise in recent years though which makes it hard to justify giving them their own wikis. Yoshi definitely can't handle it, its too small and Wario like DK is already covered extremely well by the Mariowiki. Wario may have successfully spun-off and Mario may be the spin-off of DK but Mario is the bigger name and the connections of Wario/DK to Mario allowed them to be covered by Mariowiki and they are already covered well.
Yes, we should let them develop before coming to any conclusions. I think a problem arises only if the Super Mario Wiki covers Donkey Kong so heavily that there is nothing DK Wiki can do to surpass them in coverage (for example, if Super Mario Wiki has covered every single thing involving Donkey Kong).
Simply, the coverage issue will grow as the wikis do. In my opinion, to delay a decision would be unwise. It's best to tackle the issue before it gets too big. There are a couple options out there - a merge as equals, an absorption of DK Wiki, an end to DK coverage on SMW, etc.
This is a decision that the staff of both wikis will have to discuss. In the end, it is up to the wikis what they do, but it would be of great benefit to at least consider our opinions.
Well the problem is Mariowiki covers the franchise of DK so well already, there is not enough for DK Wiki to differentiate from it, like I said I hope they do but I don't think they can. Like I explained earlier in the post, Mario may be the spin-off of DK but Mario is the bigger name and DK is technically part of the same 'universe' which is why it has to be covered by the Mariowiki. DK re-made its own name as a separate franchise with DKC series but after that its just basically clinged back to Mario making it even more integral for Mariowiki to cover it. Theres really not much for the DKWiki to cover that Mariowiki hasn't, most of it is all overlap. Now technically Mariowiki should leave DK exclusively to the DKWiki but I don't think its fair for Mariowiki to give up so much of their hardwork.