nsbin/backup-smaller-dirs

i=0
dir=0

max_files_per_dir=100

mkdir -p $dir

for a in $@; do
   if [ $i = $max_files_per_dir ]; then
      ((dir+=1))
      mkdir -p $dir
      i=0
   fi
   
   mv -i "$a" $dir
   ((i+=1))
done