Forgot to mention Stormtrooper Han might be the only exception for a tank that speed does well on. He is great if you can get him going first to taunt so he starts granting turn meter to all your allies whenever he gets hit. Also the reason crouching rancor says put speed on everything is because when you get to level 85 and your arena squad is almost exactly the same as the person who is fighting you or you are facing speed will make all the difference if your characters get to take actions before theirs.
I'm glad I could help, just try to keep in mind with your team what abilities you might want to happen first and that is why speed is important. Also I have been playing since launch I do not have mods that have +10 or +15 speed in the secondary stat on the mods. I have to use the speed set from the mod challenges to get the % increase when using 4 speed mods.
