SOLUTION / ANSWER:

Turns out its was Systems Center that was using the NT AUTHORITY\SYSTEM account to execute 50+ queries each via its own Connection/SPID. Systems Center is using the Microsoft Monitoring Agent (a windows service) to execute T-SQL queries via Windows Scripting Host. It does this every 15 minutes throughout the day. I'm not the pone who handles Systems Center here but the guy that does told me its probably the SQL Server manage net Pack that's doing this.

It also turns out its not causing the latency issues we've been troubleshooting but it is behind these 50+ simultaneous logins and now we know.