Wrong, the 4 men squads have nothing to do with them being elite or not, its to support army design of combined arms, you can NOT rely on grens alone, you need supporting units, either support weapons or command bunker/251 for map presence.
Grens never were supposed to be superior to any other infantry squad, so your elite argument desn't apply, they are supposed to be equal to cons and surpass them with weapon upgrades. Vs brits and UKF you have to use support units, just like UKF needs to do to support tommies.
Of course a squad of 4 man indicates a more elite status than a comparatible squad of 6 men: A gren entity has a better performance per entity (more average dps per and better rec_acc) than the average entity of a conscript.
You are right in the sense that the 4-man squad as a whole is of course not necessarily "better" - but the individual entity is. From the game design point of view it's just a different kind of approach: fewer men but more damage per men & better protection vs more men but less damage per men & worse protection.
In general, this approach doesnt sound that bad and actually captures pretty well the "lore" of the CoH setting. However, we all know that in game-reality shows us again and again that a 4-man squad has a huge problem which isnt incorporated in this approach: the higher wipe chance.