Honestly on the 'imperial' diplomacy map I posted it isn't that unbalanced. France, England and Russia (possibly Holland too) the countries with immense amounts of SCs would be fighting on multiple fronts almost immediately.
Russia would probably be in conflict with Japan, China, Prussia or Austria and the Ottoman empire almost immediately if it doesn't concede many of the possible gains. The lack of more than one navy in the east puts Russia at a serious disadvantage against Japan as well.
England could easily lose the Falklands, Singapore, Hong Kong and possibly Gibraltar by the end of the first year. The Canadian territories would also be under serious threat if the USA and the CSA made peace. If that does happen all England has is his/her Europe SCs, India SCs and Australia/New Zealand (which are isolated enough to protect pretty easily). If you really think about it you probably wouldn't be fighting the entirety of any sides forces either - you'd probably end up fighting British India or British America rather than facing of against the entire British empire.
France isn't quite as fragile as Britain but it isn't hard to imagine France losing all South American, all Indochinese or all African SCs with some applied effort. Ultimately ending up a little weaker than Britain without the large and secure possible gains in India and Oceania.
Finally, Holland only really has an SC in South America, and two sizeable colonies South Africa and Indonesia. It is diverse but its European SC could easily vanish without support from one of the other three neighbouring powers.
I personally believe that the smaller powers are not that disadvantaged in relation to the bigger ones either as the bigger ones will simply be fighting more wars.
I also think the map I posted is actually comparable to playing multiple diplomacy games within a larger game. North America is arguably a 4-man individual diplomacy game. Russia-China-Japan is a three-man diplomacy game. Europe is a 6-man diplomacy game and Africa a 3-man. Once the 'hot' areas are resolved you then begin to see inter-continental exchanges China-British India maybe, Australia-Indonesia, Brazil-CSA or Mexico and so on.
If it isn't obvious yet I really enjoyed that forty-five minutes analyzing possible strategies within that map :P