Well, monsters in 3E did have that, too. Just derived numbers were according to similar rule as PC. But monsters sure don't follow 25 or 32 point buy when creating their stats.
Balancing SR is not exactly easy, I think, but knowing the dice pool ranges of the PCs will get you a long way. Now you just don't have to underestimate - or overestimate spells, equipment and numbers.
Well, the other strength of SR that I found was that given a GM screen, it was trivial to adjust the numbers of the opposition on the fly without anyone but me knowing. (there were some cases involving magic where the target # was the target's stat, and everyone knows what the damage code of a particular gun is) but when rolling, the number of dice could change from roll to roll legitimately. I used this as a safety net, I must admit.
But the goals of a game of SR for my group were not the same as the goals of the same players when playing D&D. They spent up to 3/4 of the session designing the plan. Up to 12 people (a number I wouldn't want to run D&D for) sitting around a conference table hammering out a plan that they would then see how long they could get to survive enemy contact, (Not very long, typically) and then whether their contingency plans were any good. The goal was to get in and out with nobody the wiser and no rounds expended.
In D&D they want to kill things and loot their stuff. There's plenty of RP, don't get me wrong; and I've run a couple of successful mysteries/investigations successfully. (In 3E they were more successful than the majority of my dungeon crawls, to be honest; due to the difficulty I had with the mechanics of that system).
To bring this back on track; in the only system that I've run recently, did the mechanical expressions of non-combat abilities matter, and that was 3E D&D. In SR, it didn't matter because the system was so loose and because of the way PCs interacted with the NPCs. 4e brings a lot of that to D&D IMHO without having to bend the rules; and shows you what the numbers should be at every level to avoid having to fudge. (Something SR didn't do as well as it could, but running 4-12 hr sessions with a large number of college-trained engineers all of whom have a paperback-a-day habit and like the genre as reading and movie material will teach you quick). 3E always seemed too constrained to me, with way too much prep time involved. It didn't help that once you leave college, your free time to game drops drastically, so I didn't have the time to prep. But I never had to prep for SR - I could take a briefcase, a Johnson, and an antagonist's name (15 minute prep tops) and spin a night's fun out of that without cracking a rulebook. I still haven't achieved that in D&D, and I doubt I ever will totally because D&D opponents are more than a collection of numbers interacting with known and generic values for gear. (I could come close if I wanted to run only PC-race antagonists using p42 DMG and the class templates, I suppose). But I don't need to know the rules for what Graz'zt can do out of combat - he can do anything that the plot calls for and his background allows, even if it involves the PCs. If he ties a rope around the PCs I don't roll his dice, I look up how well (more or less) he should tie up a PC on the table on p42. If I want a degree of randomness I'll roll a small die (d4 to d8) to adjust the value; and use that as the DC for the escape test. There should be multiple ways for a PC to succeed or fail to advance, but they need to advance to continue telling the story. Advancing the story can involve failing at a task
Call that gamey if you like, but I've always been more interested in telling a story than running the PCs through the maze of life.