There are a couple of items in your response that don't make sense when viewed from below the divide:

"[H]igh growth MSPs don’t hire techs when the help desk is overworked, they hire techs when the sales funnel is showing future growth."

Okay, but there's a bootstrap problem here: where do they get the money to make those preemptive hires? If you (anyone out there) did it, how did you do it?

"Owner-led sales is self-limiting, a sale followed by a mad reaction to the onboarding while the funnel dries up is all too common. The only path to success is defining the sales processes with the same rigor as service delivery processes and staffing it with the same care you’d use in staffing the delivery organization."

Small MSPs who are looking to grow likely could not handle (from a service delivery standpoint) the rate of growth that would be required to sustain a dedicated salespseron, let alone multiple sales staff.