Hve to say I am not sold.
The belief the points are balanced is flawed. Mainly because many specialist CC troops that cost the same amount as marines are in fact less effective than marines due to the S and T of marines combined with AS making them hard to kill in close combat due to the statistical difference in WS and S. For instance I'd rather be WS3 S4 I3 than WS4 S3 I4... I'll hit on 3's but wound on 5's.... 22% chance of a kill.. WS3 S4 I3 will hit on 4's wound on 3's... 33% chance to kill.
He goes first true... so out of 100 times he kill the opponent 22 times before the opponent can react.
Opponent therefore only has 78 times... he will still kill higher WS and I 26 times...
This disparity is shown clearly in many of the High WS and I troops.
Since you're obviously thinking of a particular unit of "specialist CC troops", please stop beating around the bush and tell us what you're comparing to space marines. This will allow us to have a more focused and productive discussion.
Because honestly? I have no idea what you're talking about. There are several specialist close combat troops priced similarly to marines that I can think of, and of those there are a few that would not fare well against them. But what you're ignoring is that those choices usually are
quite good indeed at killing something else. You seem to be falling into that most common of traps: Comparing everything to Space Marines because that's what you see all the time. The choices you're thinking of may not be points effective against tactical marines, but this does not necessarily mean that they are miscosted, it just means that they
shouldn't be attacking tactical marines. This is pretty obvious, so without more information about your particular gripe, you aren't going to be able to demonstrate that your argument makes sense.
So, again, what unit are you thinking of that, for its points cost, stats, special rules, and equipment, should be good against Tactical Marines but isn't? Remembering that Tactical Marines are specifically designed to be effective and resilient against all opponents, where most other units are not. I am skeptical that WS is a main factor in the cost of whatever unit you are thinking of and
very skeptical that their cost would be much diminished whilst their effectiveness remains mostly unaffected if their WS was lower.
Your statement about how you would rather swap a point of WS for a point of S is also not making sense to me, because there are certain guidelines to what S and T can be that have nothing to do with effectiveness. For example, it doesn't matter how much more effective a WS 2 T4 Eldar Storm Guardian would be than a WS3 T3 one, because there are no T4 Eldar.