What would you term major success? I think even @glasgowspur is being very ambitious by saying 2 or 3 domestic trophies, a European trophy and consistent top 4 finishes.
For me, if we keep him for 5 years under this ownership model, I'd take consistent top 6 finishes with a few top 4 finishes and a domestic trophy or two as huge success. I know sometimes you can get a little run of trophies once you win one but we haven't won one in 15 years (and haven't won a big one in 32 years) so if Ange breaks that duck, he's done brilliantly. I'd also add the above must be achieved playing entertaining football but I think that's a given with Ange.
I think we will challenge for the title next year and I honestly think we are on the cusp of something as a club which will see us become regular challengers. In massive part for the reasons I droned on about the other day. Anyway with all that combined I have Ange nailed on to win things with us