First of all English is not my first language so keep that in mind pls
What I want to say is Pre-made group of 4 ppl in random WZ is breaking PvP in SWTOR.
And now why I think so.
WZ match is 8vs8 so if pre-made grp joins its half of the team, half of the team are working as 1 brain, that guarantees them 90-95% win rate IF they dont meet another pre-made. You dont need to be too skilled for that cos with right coordination even lower than average players can steamroll random WZ. Gear? With current bolster system noone cares for gear.
All of that is getting worse seeing at what point healing is now at PvP, healers just wear PvE gear and require A LOT of effort to be killed EVEN by 2 dps. So when such healer is a part of pre-made he also gets shield and taunts usually and 2 pocket DPS who eat everyone who looks at him.
I personally usually play alone or in group of 2 ppl, and meeting such pre-mades every 2nd game is kinda boring cos there is nothing I can do, i try to coordinate with my team, try to achieve victory (not mindlessly killing RED PLAYERS) but steamroll is a steamroll.
Also I want to give an example of how developers care for balance in another online game. World of tanks is a pure PvP game where battles are 15vs15. The group limit for a random battle is 3 ppl (its 1/5 of the team not 1/2) and still GOOD players usually have 80% win rate with group of 3. When developers were asked if they plan to increase the group size the aswer was smth like- "Absolutely NO, it will kill any intrest in the game".
My suggestion is very simple. Maximum group size for WZ- 2 men, for everything else- Rated.