This is all nonsense. Too many bad decisions on "balance" have already been made because someone with influence didnt like losing to a tactical play by an opponent.
There needs to be a critical mass point where defence can no longer deny offence especially when the offensive tool costs more.
If you argue for this you also would have to agree that an overwhelming number of t3 static arty should not be enough to break through shields...
A tml plus its missle almost costs as much as a tmd plus a t2 mex. You are arguing that you should be able to get an eco advantage of +4 mass with no downside risk in simple terms. The fact that a tml is able to strike multiple targets just makes it a better decision to make than the t2 mex in some situations so your point as a whole doesnt stand up when having to generalize how to fix it as you desire due to your recent experience.
The t3 mex dying to 1 tml of course is bad i agree but that is as a consequence of a bad decision to make hp on mexes and pgen different per faction. Again that is the result of a bad decision in the past (post august 2016 balance patches).
I was in favor of closing the gap of damage between tml and bombs by strats a bit in line with a general reduction in hp of stuff but i have no say so what does it matter whether my proposal is better than what is there now