It looks like the distance you can shoot, at that range, is fixed, seven and 25 yds.
If the .22s are going to be your only guns, are they also going to be your defense weapons?
If so, then target sizes should reflect the effectiveness of the .22 - namely head or center of mass, rapidly fired.
3" to 4" diameter targets, at seven yards, should do.
5" to 6" max, at 25 yds.
Longer than these is good, too.
50 yds with a .22, especially a rifle, is not hard, at all.
One of the advantages of the .22 is excellent accuracy and low recoil, allowing very fast multiple shots.
Try these and see.
Walt Kelly, alias Pogo, sez:
“Don't take life so serious, son, it ain't nohow permanent.”