What I think could be better, is make the t3 scs 31-39. Then t4 can then be split up into a couple more tiers by rr. Maybe something like rr 40-59 for lower tier, then 60-80 for higher. This means that everyone in your group must be rr 60+ if you want to queue for that tier, or rr 40+ (and not bigger than 59 ofc) for the lower tier. You can make one or two scs for each tier be specifically for 6 man groups, if they wish to do 6v6. That way you won't be getting rr 40-60 groups fighting rr70-80 ones, or even full 80 groups, which I would think there are a couple on the server. I think it would also allow people to fight in a level playing field, against opponents with similar skill, which means it will be easier to gain experience with your group as you fight through the tiers, eventually coming up against the higher premades to test what you learned. Well that would be the ideal world at least. The same system would be for pug scs, 40-59 and 60-80 (although there probably isn't enough people for that now, and would split the population even more). All of this can be done for rvr as well (not exactly the same though). Maybe it's just me, but I feel the quality of rvr has gone down significantly since the inclusion of rank 16+ players (if you think it's enjoyable for premade wb to melt a lowbie pug wb you're wrong, it's exactly the same like in scs).
Separate the tiers to low tier, mid tier and high tier. Mid tier being rank 16-39, high tier rank 40+. Anyway, this is for another topic.
The sc system I mentioned would also keep high level players from fighting rank 31 lowbies of course. There is just no fun in that (at least for the majority I hope). It sucks even in pug sc when your group is made 80% from lowbies (it can happen and has happened to me and many others I'm sure). Now imagine if a premade was on the other side. Waste of time for everyone. No one learns anything, lowbies get no xp or rp, and the premade is just bored. Just don't tell me 'well they can at least try and fight'. Everyone knows how quickly lowbies explode against premades, a whole group can die literally within a minute. How does it even make sense to fight then, and how would people not feel like **** after that. You literally can't do anything. Well it's similar when a new premade fights a vastly better one. They get steam rolled a couple of times and lose motivation.
People need room for developing. You can't just toss then into the fire, no matter in what aspect of the game. They will just get frustrated and disappointed. The tier system I explained would also split people up by available gear. What will happen when sovereign, warlord, tyrant and what ever else gets released? Can you even imagine full sov groups/players fighting rank 31s? Absolute massacre (not that it's much different now, can't even imagine with higher gear). I know devs said many times that there won't be huge power creeps, and I'm glad for that. But gear still makes a difference. Maybe it's not a huge difference when two good groups are fighting, but for pugs it is. How much boost will the lowbies need then? They will still miss a tactic slot, mastery abilities and what not (main thing for me being experience with the game/archetype they play).