More countries because it would allow more effective self-governance and it would remove power from individual countries themselves.
However, this isn't that viable to do when you have gigantic nations like the USA, Russia and China, that can do whatever they like without the fear of consequence.
But in general countries shouldn't have a divided society, but instead just large enough for there to be unity among people.
Also Russia is only playing on the desire for people to secede from the country, as the people themselves are split between the East and West of Ukraine. Russia is also trying to do the same in opposing countries by agitating the people within.
Europe alone has a shitload of them, so it wouldn't be that hard to cause in-fighting.
https://en.wikipedia.org/wiki/List_of_active_separatist_movements_in_EuropePutin didn't really need to do much, he just needed to give them guns and then cause the Ukranian government to go overboard for the people to decide to fight for independence on their own, although he did send some support.