I'm with MaruMaru.
I'm sure I'll get 3/4 GLs & maybe 4/4. Why? Those factions need improvement over time anyway, so why not collect the GL while we're at it? The only thing stopping me from collecting SEE at all would be if a new GL was released before I got SEE, and he was demoted to "desirable, but have to wait a bit longer". Theoretically that could happen multiple times, but I'm not really worried about it. There's going to come a time when boosting Empire makes sense, and there are several sith who have long been on my "desirable, but have to wait a bit longer" list. There's got to come a day where they hit the top of list, and then I'll pick up SEE as well.
Stop playing and come back in 10 years, you will still have the best squad in the game and there will be 10.000 players with 10.000 SLKR squads
What? No. If everyone on your Arena shard was running SLKR, you just run JML & race up the ladder to take #1 that much easier than another mirror match.
Plus they also have the option of squad power creep without toon power creep. Add a toon with the right kit & synergies to resistance and Rey becomes very difficult to beat by SLKR without releasing any toons that are outright more powerful than SLKR. Suddenly Palp, who has an easier time with Rey, becomes necessary.
Not only would too much of one GL naturally tempt people to grab a GL counter to that squad, but no power creep in toons could still allow power creep in squads, which allows a shift in the power to rebalance and encourages players to use a different toon for most Arena purposes.
GLs were a huge power jump. We can't have ongoing power creep from these new heights, at least not anytime soon. But power creep of non-GL toons can continue, and sometime in the future when it's more reasonable (certainly not before March 2021, preferably not before Jun 2021) they can start thinking about a pair of GLs that provide a small amount of power creep again.
And, of course, on top of all that, there's power creep from 6A mods (and eventually 7A mods) & possibly "Relic Abilities" which CG has mentioned before as a possibility.
Even if there was no "power creep" in the sense of a single new toon that was decisively better than SLKR, you would still come back 10 years later and find yourself hopelessly behind & in desperate need of new toons & new resources for new upgrades.