I think it's a great idea but would you be able to fill a Fixture card with friendly matches
Not unless all the other clubs around us did the same thing, no: hence why we're not even going to try.
Playing outside a league does have its advantages - for my T20 team, if an opponent messes us around, doesn't turn up, don't play in the right spirit, we simply don't organise a fixture against them next year.
Whereas for our league team, there are teams in our league who have forfeited 5 of the past 6 fixtures we'd had against them, but we will still be given 2 more fixtures against them next year, which, no doubt, 11 of our guys will give up their weekends for only to find they forfeit again at the last minute.