I hope most fans share your realism. I'm still looking at who's coming up and hoping they'll be shite, such is my general outlook. Dundee are usually a comedy outfit so that's a good start.
Elsewhere, though, Motherwell have been excellent since Kettlewell took over. Aberdeen should improve. Hibs have looked like the league's 5th best side under Johnson and I'd expect that to continue. Unsure about Naismith at Hearts but can't imagine they'll implode again.
Livi and the Fakes are always competitive too.
Meanwhile, we have got assets that will be coveted and we absolutely have to play hard ball in the transfer market. By the same token, making money off in-contract players is literally our business plan, so I don't think anyone is 'safe' from leaving.
TL;Dr - League won't be any easier next season, but I have absolute faith in the management to replace anyone that does leave.