Is it ever worthy of having fundraising staff roles defined based on where the donor is on their journey with an organization?

Tim Hanson, a business guru who comes from an IT business perspective to be sure, has an impression that the work of further #stewarding existing clients, what he calls "order taking" is easier than "sales." Learm more by clicking the link below. 
 
I disagree. Both have their challenges and require innate #talents, inherent interest, and skills that can be further developed over time. 
 
Nevertheless, the point that Hanson is making may be worthy of consideration: he perceives the roles call for different skill sets in the job descriptions.
 
I'm marinating on his theory in relation to assigning roles for teams of larger individuals in #development, fundraising, and #advancementdepartments. 
 
How truly different is the work of acquiring new #donors versus growing ones that already exist?
 
Thanks to Liam Dacey for sharing his insights which inspired me today.