The biggest problem with using a smaller compressor is the amount of air it stores.
I bought a harbor freight 29 gal compressor with about 5.9cfm output at 90 psi. the issue is the 29 gallons of air stored. The compressor is constantly struggling to keep up. My solution I bought a broken Husky 60 gal compressor for 75 bucks and deleted everything but the tank, I used the tank to hold additional air so now i have about 100 pounds of air which is great.
I sprayed my entire truck and never had to slow down. there are YouTube videos on how to link the tanks it's easy. My total investment in compressors is under 400 dollars including hoses.
Gary

That’s a great idea!! I will look on marketplace and Craigslist to see if I can acomplish the same idea.