I don't know what "usual" is. I know some men & women who sponsor literally dozens of sponsees. And, I know others, who can barely get by w/ sponsoring one.
It depends on the sponsor. How long they have been sponsoring. How well they sponsor. And, how strong they've developed those that they are sponsoring.
One of the good things about being sponsored by a sponsor that has many sponsees (if they are solid AA's) is: it's like a family. You've got brothers & sisters in sobriety that also help you and the sponsor.
On the flip side -- you'll have an occasionally Ego driven person that feels personally inadequate or "less than" if they don't have a string of newcomer sponsees around them.
Good sponsors are not easy to come by. That's why I've done ALL that I can do -- to hang on to mine.
He's the best in all of AA. And, men like me -- die w/out sponsors like him. Not all alkies are like "the men like me" -- some, get the program very easy and fast and grow w/ very little sponsor effort. Some even do well w/out a sponsor. But, those I've seen that do well w/out a sponsor -- actually -- it could be said that "they are using a few AA's as their sponsors."
With all that said -- it probably doesn't help you, w/ the rest of your question. (That only covered "the usual or unusual" part).
Sobriety rule #1 = It's your life. It's your sobriety. And, quite possibly -- your life depends upon your sobriety.
Sobriety rule #2 = Use anything and anyone who can help you to achieve & maintain your sobriety -- and to assist you to grow in understanding & effectiveness. Regardless if you call them a sponsor or not.
Have you met your sponsors sponsor? You may want to get to know your sponsors sponsor, because that's like your "Grand Sponsor." (Yep. We got grandmas, grandpaws, babies & grandkids.) LOL.
One thing that all of us alkies have in common is (especially when we're new): we want lots of attention. A few of us, actually do need the attention. And, there are some of us who are attention starved. (We have a dis-ease called "more" -- a little is not enough).
I hope you've gotten a little bit out of what I answered. I'm sure it probably helped me more, to answer, than it helped you to read it. That's not intentional. I wish I could help you and everyone -- but, I realize, I'm usually of very little help, but it sure does help me to "try".
Hopefully, someone will come along here and offer you some better answers. Until then -- anything I can do to help, just yell at me.
btw: Wishing the best for you! And, thank you for participating & asking your question!
I appreciate you.