Okay that's fair. I don't think we can sleep on alpha strike + range increase given how much AA tends to shoot at fast moving aircraft that tend to get away + quickly have an opportunity to repair.
But let me take a step back, move the goalposts, and say that if the role of a unit is being changed significantly, I'd like to see the numbers worked out from first(ish) principles (say, based on the unit they're targeting) instead of suspiciously round percentages. Whenever I see +50%/+100% etc. I get the vibe there's not a ton of analysis going on behind the scenes.
So first we need to define what role SAMs play now (in relation to flak and interceptors/ASF, which both have strong identities), and what role we'd like them to play. From the OP, looks like FunkOff's suggestion is long-range, heavy hitting, and (implicitly) aerial denial. That appeals to me on multiple levels, establishes a unique identity for the unit, interesting interactions with jamming, etc. etc.
Increasing the range also A. allows SAM health to be decreased without compromising their usefulness and B. opens the door for them to rely on radar more, which makes radar more relevant as a tactical target.
Later, after we get runaway balance issues/sprinkle some salvia in our coffee we can talk about anti-missile defense (lasers, flares) for big, slow air units we don't want to get absolutely trashed by the changes. Or radar adjacency effects. Sky's the limit.