Min number of images

These are my current settings. I don’t have file backups as I do not currently have the space and I find the ability to restore a dead harddrive much more important.

The question I have is if I set min and max full images to 1 is there any chance I ever have no backup? As I don’t want it to delete a backup until the new one is finished but as soon as it finished I am ok with it deleting the previous backup.

Also are there any recommendations for number of incremental backups?