I would suggest you self-publish. Let me break down the mobile game landscape for you in a single statement:
*You can only grow a game if your LTV (Lifetime Value) is greater then your CPI (Cost Per Install).*
I assure you, that once you have that formula successful, finding money to support continued growth of your game at extremely favorable terms to yourself is not going to be a problem.
If you don't have success with the above formula, then it doesn't matter if you have a publisher, your game's not going to be able to grow and make money with them either.
There are only 2 conditions which you should consider a game publisher:
1) You need money to complete the game. (ie, no way will the game exist unless you get the money.)
2) For specific geo locations, such as China where there are people who can properly localize and market the game.
That's it. I believe there is no grey area here and I've had experience on both sides of the table, including being the first 3rd party publisher signed by Zynga. The latest game I built is currently in the top 100 grossing chart (Cookie Jam) and it's there because we have successfully cracked the formula above.
Its quite simple, but really difficult to achieve.