Your business is still solo, but after your first year you'd be stupid to be a sole proprietor, especially with a second crew, whether it's one guy or four guys on the second crew. I can cut 13-15 lawns per day in the Summer by myself with a 36" mower, apprx. 4-5 acres.
Other than that, I won't say more with out more details.
There is an Old Blue Chair for each and every one of us, we just have to find it.
2006 GMC Sierra 2500hd crew cab with 6.0 gas
Kubota L4740 w/ loader and landscape rake
Exmark Lazer Z 60"
Toro Proline 36" wb w/t-bar controls
JS46 22" walk-behind $500 piece of $h!t, don't buy one
Echo trimmers, chainsaws, pole hedge trimmer, pole saw, hedge trimmer
Husqvarna 130BT blower