Valimaki head and shoulders above the other two in terms of long term value. I see him as our 1D within the next 5 years. I don't think Tre would move him for anything short of a repugnant overpayment.
Andersson/Kylington; I see kind of the same. As of today Andersson is more valuable, but Kylington is no slouch. Both guys strike me as guys who'll be top 4D's in the league. Andersson is the more surer bet. Kylington is a question mark if he could handle 15 minutes a night playing against anything but depth, but who knows, this kid has progressed nicely throughout his pro career so far, and he's still so young.
I think the Flames will try to hold onto all 3 of them to be perfectly honest. I feel they'll keep one of Brodie or Hamonic (my guess is Hammer) and that will open up some spots. They might deal one nearing the draft, as they'll more than likely lose one regardless.
So my personal order, and likelihood to be dealt:
1) Valimaki, near zero chance of being dealt outside of a blockbuster that nets Calgary something outrageous.
2) Andersson, near zero chance of being dealt; he's a RD, he's young and the coach already trusts this kid.
3) Kylington, probably dealt closer to the expansion draft. He's a LD. He won't be better than Giordano or Hanifin (whom I also think could be Calgary's 1D), if they could really upgrade the roster, I.E get a top 6C that's age appropriate with term, they'll do that.