I don't encourage my Scouts to set thresholds for leadership positions. I encourage my Scouts to think about what the leadership position entails and vote for the Scout who can get it done.
Last year we had a Scout who had been with our Troop for 6 years and just passed the swimmers test for First Class. He just had mental block about it. He has mounds of camping experience, great Scout skills and held several other PORs in the past. He was elected SPL and did a good job. If he had failed the swimmers test again should he have been denied the chance to run for SPL, I don't think so.