here's my defense against the TO at Palanga
suffice to say they're not a problem anymore 
on VH/VH though, you need to abuse some aspects of the game or you really don't stand a chance as Lithuania... but when you do your pretty much guarnteed to win every siege defense 
As for Scandanavia, their roster is extremely infantry heavy, which means they are very very vunerable to your cavalry and horse archer heavy roster, all the viking units basically can't do jack against horse archers and/or cavalries. and once you take their settlements you can build viking raiders your self which makes you much less vunerable to their strength (siege assaults). I basically took them down all the while fighting Novogod and Kiev.
Poland isn't a recommanded target IMHO, beating them just get you into more wars with the HRE and Hungary. while if you finish Scandanvia that whole area is basically scured for good. same goes for the Russians, once you push them back a bit the Mongols should finish them off anyway. so just aim for Novogod itself and after that sit back and watch the Mongol daddies do their thing.