Steve's barking at too little to count

Now I've heard the expression too big to fail, what about banks that are too little to count.
Those are the banks that for some reason have assets that can easily be taken over by a gigantic back, making that big bank even bigger. Those banks one might consider too little too count, so they must be taken over by a bank that's too big to fail..
In the thrilling days of yesteryear a bank could go under and it would take some time but those who didn't have that much money in the bank would eventually be paid. In those thrilling days of yesteryear were one could wait to get his (or her) money out of the bank the peoples were paid in check or cash. The day of being paid by check is dying, everything now including Social Security is being payed electronically or by debit card (with the exception of my maintenance which I still have to pay by check).
My imagination is running away with daymares of what would happen to the economic system I've come to know and love if the electronic system that we have in place would stop for even several days. What kind of havoc would we have?

*A daymare is a made up word by me for scary over active imagination while one is awake.
In my not so learned opinion there is nothing wrong humongous bank if one is a savings bank or a commercial bank or an investment bank, but no co-mingling of banks.
It seems to me that ever half century or so we break up the banking system because of the co-mingling of banks almost collapses our economic system but eventually the banks come back together as if drawn by a mysterious magnetic force.