How about some actual data?
Here are the numbers of 4.5 guys on each team in our league. I will list them in order of the current team standings so you can see to what extent having 4.5 guys on the roster influences results.
If you want to be in the top of the standings, recruit 4.5 guys. If you want to be in the bottom, rely on 4.0s.
By the way, there are 155 players in our 8.0 mixed league. Figure half of these are men, so 77 guys. Seventeen of the guys are 4.5s.
-- Random Error Generator, Version 4.0
-- Master Moonballer