Thanks for the suggestion. There are two main issues with having with a promotion like this:-
Getting all the ambassadors online at the same time to fill a SNG
Running the actual league
On iPoker you alias does not change so it's much easier to track players as they play. This is not the case on Unibet where players can change their alias multiple times a day and it can be easy to forgot to change it before the start of a league game. Now we could enforce a "same alias" policy in order to win points but it would still require manual checking and recording of each game and league updating. In order to automate the leaderboard it would require dev time from Relax and I just don't think we could justify the resources for something that may only have >50 players enter on a regular basis.
On the ambassador side, Ian regularly plays SNGs at the end of his session with viewers of his stream already and although they don't have big prizes for the winners they do enhance the community spirit you mentioned.
There are a number of community driven promotions that already exist, The Community league for example, along with all the streamer added value games that run weekly that get everyone involved. I do think your idea of a SNG with the ambassadors would be a great promotion for if/when we run a live Unibet Open and can send a couple players to a location to play the SNG live.