This question applies to all fighting games but I’ll use Killer Instinct for my example… I currently main Hisako and pocket Arbiter, Glacius, Rash, and Eyedol… Possibly Gargos in the future…
So would you consider this too much?
If yes, why?
If no, why? and how many pockets do you have??
Nope. Never to many. Get good at as many characters as you can. It makes you more versatile and less predictable.
I main Riptor, but pocket Rash, Arbiter, RAAM, Cinder, Thunder, and Eyedol.
I main random select and pocket every character.
Those Random mirror matches are always 6-6
Yeah. Kinda same here. I mean, I have my preferences, but you learn skills that can apply to everyone on the roster. The only one I really suck at is Aganos.
1 v 1 me Hisako vs Aganos m8
Can’t. Don’t have gold.
You can never have too many.
How dare you steal three of my pockets DDDDD:
I main Aganos and have everyone else, minus the creepy spider-lady, in my pocket.
Just to clarify, a pocket character is a character who you don’t main, but you have enough knowledge and skill with it to be confident about using him.
They are often used as counterpick.
For example, if you main Aganos, you may struggle against Sadira. You could have a pocket Gargos, who wins Sadira, and use him to face the spider lady, increasing your winning chances
I co-main Aganos and Gargos, and I have a pocket Eyedol and a pocket Raam
Also, learning Kilgore to be a possible pocket character
I forgot to say I don’t have Kilgore yet. I wonder if you can still get him from random select. Can anyone confirm?
I can’t, since I already have him 
I feel like i’ve been able to play against Kilgore on random select but not as him.
I think you have too many pocket characters when it begins to hurt your proficiency with your main. If your main’s best punishes, sequences, and resets are not second nature to you, then you should focus more on him/her. This applies even at high level - if you have to think about what you’re doing with your main, then you’ve got too much going on on the side. The instant you decide a response to a given situation, you should be able to respond appropriately.
And for the sake of clarity, I consider a pocket a character who you would be confident playing in a serious competition (with friends, at a tournament) in lieu of your main. I can play about 6 characters at a reasonably high level (good enough to take on most forum-goers), but only about two of those are at a level where I’d even consider using them in a competition. My main (Hisako) is far and away my best character though, so to be honest I’m not sure I’d even consider my best two alternates true pocket characters.
You know you have too many pocket characters when you can’t remember the ultra commands and lose the game because of it
If you don’t end the match with an ultra it isn’t a true win.
Fascinating to hear the different definitions of pocket. I don’t have that stellar a win % with my “main” so I think of a pocket as any character that I expect I could use at a significantly higher level than a random pick and for whom I would expect to situationally perform better than my main.
At this point I probably only have a pocket Tusk and I counterpick against Shago. I may also use him for Spinal and Fulgore because he deals with teleports much better than Glacius and Sadira because he handles her air pressure way better.
If you can handle pocketing everybody that would be ideal. But I can barely keep up with two (and actually I need a lot more repetition with Glacius to really start getting better).
I love pockets 
I have shorts with lots of pockets, jeans with a lot of pockets, and a coat with lots of pockets. I even like it when my shirts have a pocket. Deep pockets are also nice, because nothing falls out when you sit down. Zip pockets are also great for cell phones.
Now back on pocket or topic 
I think anymore than 3 pocket characters and a person starts to get confused and mixing up what commands do which moves between the characters. It is easy to notice this when you put on lots of pressure.