This is getting obscene. Anyone trying to get into the game now is going to be facing a dauntless task of obtaining nearly a dozen required teams for other toons before they can actually make their OWN teams to enjoy the game. Every time you hide another unit behind another required team, it just sets every player that much further back from being able to do what they may WANT to do. You've shut down any attempt at flexibility and creativity by telling people "no, you MUST grind these units instead."
Look at the units required right now (All, of course, need to be 7*'d):
Emperor Palpatine - 5 Rebel units
Thrawn - 5 Phoenix units (out of 6)
R2-D2 - 5 Empire units
BB-8 - 5 First Order units
Chewbacca - 5 Bounty Hunter units
Grand Master Yoda - 5 Jedi units
C-3PO - 5 Ewok units (out of 7)
Commander Luke Skywalker: Luke Skywalker (Farmboy), Princess Leia, R2-D2, Stormtrooper Han, Obi-Wan Kenobi (Old Ben)
Jedi Training Rei: Rey (Scavenger), Finn, BB-8, Veteran Smuggler Han Solo, Veteran Smuggerl Chewbacca
Jedi Knight Revan: Bastila Shan, Jolee Bindo, T3-M4, Mission Vao, Zaalbar
Darth Revan: Bastila Shan (Fallen), Canderous Ordo, Carth Onasi, HK-47, Juhani
Darth Malak: Jedi Knight Revan, Darth Revan
Han's Millennium Falcon (Han Solo (Raid), Chewbacca (event)): Hound's Tooth (Bossk), Slave One (Boba Fett), Xanadu Blood (Cad Bane), IG-2000 (IG-88). ("Requires four Bounty Hunter ships", these are currently the only four.)
Chimera (Thawn): Rebel ships.
Territory Battles contain Rebel Officer Leia Organa, and Imperial Probe Droid. Will update next time requirements are confirmed.
That's 11 teams of 5 characters each, sometimes generic, sometimes specific. As well as some specific characters, and ships. And while there is some overlap (Phoenix has 2 Jedi, JKR has two Jedi, etc.), for the most part you are having to grind almost fifty characters, just to get the specific characters in the game. Which means if you want to just focus on teams for FUN, but want to actually collect the characters available, your priority to enjoy the game is going to be pushed back a year or more.
That's far, far too many teams to force players down. You have 167 characters in the game, and 2/3 are rendered moot because players have to wait so long before even attempting to get them.
Players should be able to go after the characters and teams they WANT, ones that appeal to them. Ones that amuse them. Not being forced down team after team after team of endless grinding for the powerful meta chars. Especially not down so many.