I think Arizona declines. Garland will take a lot.

Dubes legit and he just turned 22. He's one step away from being a consistent top 6 forward and he creates a lot on his own, has jets and a sneaky good release. Dube + 12 overall is a pretty good deal for Arizona.
Garland is a great player but he is 25 already, only has 3 seasons (none of them full) and has scored at a 0.59 p/gp pace so far in his 3 seasons.

Take off the fourth and that’s pretty close for Foegele

If I’m Calgary I’m declining. Other than this last season Monahan is a certified 20 goal scoring centre and Dube is one of the best prospects Calgary has had in a while. If he can find the form he had in bubble last year he’s already close to Garlands value with him being 3/4 years younger plus Monahan and a first that’s a no on Calgary’s end for me

From a strictly asset-to-asset value comparison, I'd agree. I think Arizona is getting the better value.
However, I think it's important to consider a few other perspectives: Team window/capstructures/current player development and overall team structure.

I think with Dvorak and Garlands age/cap they fit perfectly into the flames window (assuming they are trying to compete with Darryl Sutter/Markstroms contracts).
I also think that this is an overall better team structure that aligns more with what Sutter is trying to accomplish. Dvorak is a more aggressive forechecker and a better overall skater then monahan. Garland is a step ahead in his career then Dube and also a RHS which the flames desperately need more of.

Given the flames situation and their competitive window, I would rather my second line be:
mang - dvorak - Garland
vs
mang - Monahan - Dube

Edit: Ideally you could remove the first and include a second or equivalent value. However, given the current perception on monahan and the difference between dube and garland, I included the first