Mixed Side GST Team Variations:
Mother ('12-'13): Dante, Clops, iHercules, Abel, (Red Leo, Poodie)
Deity ('13): Dae, Eko, Ruke, Fulgore, Exalt
Alumni ('13-'18): Thallen, Eko, Dante, MK, David, (Aguzo, Dae, Ares, Skull, Fulgore, John, RM)
Apostles ('13-'16): PrimeTime, Skull, 6Jack9, (Aguzo, Zideruic, iHercules, Male)
Blackout ('14-'18): Brett, Zideruic, Aguzo, Sean, Dark
Memory ('14): Talbourn, Ph8, Felix, Smoke, Hero
SLX ('12-'16): Demrow, Aserus, (Skull, Male, simpLe, Majin, Zet)
SNC ('12-'15): Ethereal, Advocate, Kosma, SK, Exalt
GTeam (‘13-‘16): Chun, MaxyMax, Ruppy, Xanji, Ariona

These are pretty inaccurate, but gives basic shell of 'teams' rather than judging an individual. I just did this without researching too much, each guilds had their own era with core players. people in parenthesis are changed/replaced later. Also I didn't mention US, cause i didn't play back in 2011, but we know who they are.
Core players are important IMO, they decide if the guild lives on or not. They contribute lot to guild's history.

Same goes to iDevice, but I don't remember much. I just know there's core players around Fros team, Sarahs team, Comyts team, vDragz lasted pretty long and Silvers team. Not sure who else im missing out, but you iDevice know who the competitive guilds were. Whether they lasted 1 season or 1 year, if they made significant challenge in GST, it matters tbh.

I don't think Alumni is really Alumni without David or anyone we know they were in Alumni for long time. They all represent their guild.