Seem to be the most successful human players, in no small part because you would be each others natural rivals in a normal game.
In a normal game any of the three italian players would have taken the other italian nations a long time ago
Talking about the most successful human players, I would probably rank it like this, and in general agree with you (note, this is of course from my point of view, I dont have complete control over how easy it is to play all the countries etc):
1. Naples/Fitz/Colkate - have become the strongest human player in Europe and have managed to do so without struggling even once as far as I can see. Great player. Did get some luck and help early on, but has simply been doing all the right choices from there.
2. Viyajanagar/Toma - more or less unified India is one thing, starting to westernize (and maybe finish it now?) is something completely different and was enough to push Kabouter to quit which in itself is a huge victory for him.
3. Sardinia-Piemonte/Savoy/Morfeo - I think I have done decent considering I started so close to human players like Burgundy, Venice and Naples, and also lost an important ally when Austria got player-controlled. Have stagnated and not really progressed the last few weeks though.
4. Venice/Archenemesis - Have done well by taking over most of balkans, and I think I would have placed him above myself if he hadnt gotten a friendly player to take Austria pretty early in the game. Also has limited possibilities going forward which makes his situation a bit dire, but have done fantastic from where he started.
5. Japan/Hosokawa/Mgo - I dont really know how hard it is to play a daimyo with success as I have never done it myself, but I will guess that its challenging for the first roughly 20 years, and then pretty easy as there is no real threats. Have probably done more or less as well as possible considering the situation though.
6. Hedjaz/Sickboy - I have never tried to play them so this is just pure speculation, but has done well to avoid the Mameluk threat, ally with the ottomans (before they became a joke), and unite Arabia. Looks to have a dire future with a strengthening Hindustan approaching though.
7. Ming/Kabouter - From what I can judge he did more or less everything right when he played, but drops down a bit here since he gave up early, and also because his future would be almost certain doom at the hand of Toma.
8. Novgorord/Crabby - have expanded a lot considering his tricky neighbour, and also secured a strong alliance with Poland that has been very favourable for him as far as I can judge. Have stagnated the last few sessions though, and doesnt seem to be able to get any further from now on considering how strong Muscovy is becomming, which drops him down a bit.
9.Poland/Manik/Cazz - looked awesomely strong after a few sessions, but have since lost Lithunia and hasnt really done a lot to expand in any directions. Did finally take some crimean provinces last week, but I feel he should have been much bigger considering how strong Poland starts out.
10. Burgundy/Fanboi - is just slightly stronger then when he started out, but has the hardest country as his main enemy, so that might be as expected. Is probably fighting a loosing war against France that will eventually make him irrelevant in the west. Was probably just a bit to aggressive early on, and hasnt really recovered his strength since.
11.Morrocco/Mleuigi - A hard nation to play for sure, making it difficult to judge, but he have been lucky that player-controlled Spain and myself hasnt been more aggressive, giving him a free hand to colonize and do whatever. Does have some challenge from Portugal and the AI-Spain when Digby doesnt show up, but should probably be bigger than he is. Joined late, so that might be a reason.
12. Spain/Castille/Face/Sir Digby - plays the easiest nation in the game and have just recently been able to unite the thrones of Aragon and Castille. Was a n00b when he started, and is better now, so will probably do much better in the next game.
13. Austria/Wallachia/KingSnake - had an uberhardcore game with Wallachia going that actually went ok before the unavoidable annexation. Then switced to what probably was the third most powerful country in Europe at the time, waged a ton of stupid wars in the swiss mountains, Bavaria and Hungary - and hasnt really recovered since. Was heavily overextended for a long time, got tons of rebels, religious wars, bankrupcy - and lost the imperial throne. Have recently been able to recover somewhat and restart his expansion, but considering the nation he plays, he should be dominating the empire by now.
14. Scotland/Mali/Rug Monkey - The AI Scotland started out by taking a few english provinces, giving Rug an excellent start, but has since been loosing war after war before eventually getting completely annexed. Switched to Mali where he doesnt seem to have done much. Difficult to judge, but definitely hasnt had a successfull game.
15. Denmark/Sweden/Georgia/Wink - started out in a superhardcore impossible-to-win situation in the kaukasus, but it was his terrible performance as Sweden that scores him this position. One of the strongest nations in his region, he got decimated to the fact that he changed to Denmark - and as far as I can see hasnt really done a lot with his new country since. Scores last for failling with Sweden mostly.
So this is of course only from the perspective of the peaceful savoyan, there might be random events and a ton of other stuff I am not aware of, and I am sure there are good players that have been unlucky in this game, and less good players (like myself) with luck etc, but at least this is how I would rank the human players in our game from Turin.