I am a huge fan of the concept of a county wide dept ... but .... the county wide dept. in an of itself will not place more firemen in bedroom communities during daytime hours, and it probably wont cause a flood of volunteers.
IMHO, there are two factors that might enhance daytime response with a county-wide fire department:
1. Consistant requirements and expectations county-wide might increase the number of firefighters. With county-level management, the social club aspect would likely fade into the sunset.
2. Since all stations would be under the same management, there is the possibility that someone who lives in one area of the county but works in another might well be able to run out of the station where they work as well. Of course, all the other factors that affect responding from work also come into play - one-deep positions, out-of-state employers, etc.