In the VAFA (where the grand finalists both get promoted) there's the first target for each club, which is making finals, then making the grand final (which means promotion), then winning a flag.
Clubs want to get promoted year on year if they can, and if they win flags in the process, then that's great.
I'm sure any club would prefer to be a runner up in 2017, and stay up in the higher grade 2018 as opposed to winning a flag in 2017, the getting relegated in back down in 2018.
Hence I'd value the promotion at 80% of the season aim, and the flag that extra 20% on top.
Agreed. I'd also add that at many clubs the ultimate premiership is the one in A Grade and in order to win that one you have to be there. Caulfield is still some way from another A Grade flag, but are closer now with that win on the weekend.
Having been down at Glenhuntly for some time now, I can say that the 1970 A Grade Premiership is held as the club's ultimate success, closely followed by the 2011 B Grade flag. But every club is different.