Not sure of your context here.
"shared"...."local admin account"....on a "server".
This "server"...is it a "domain controller"? Usually on a DC, once you've promoted it to a DC, you always log in with a "domain admin" account...not a local account. Same with member servers of that domain, once you've joined the domain, you always log in with a domain admin account. Technically you can log in with a local account..but...it's just...there's no purpose to that, you don't use that again.
"shared"....very rarely, with just a few clients that are larger and have their own in-house IT people...they will have their domain user admin accounts that they log in with...and we're comfortable with their knowledge of administering the server. If that's what you mean by "shared"...as in...allowing the client to log into the server. Majority of our clients don't log in, they don't know what they're doing, and we'd prefer they stay out...they have us to do that stuff.