I'll try to take a stab at explaining why I think this was done.
The first link you have posted is for the no longer used VHF radio system. All of the Minnesota State Patrol communications are now conducted on the ARMER radio system, which is a state-wide trunking system.
Allied Radio Matrix for Emergency Response (ARMER) Trunking System, Various, Minnesota - Scanner Frequencies Your second link is for one of the districts for the MSP on this system.
The newer Uniden scanners (HP series) have, similar to your 96 series scanner, location controlled scanning. There are two "components" to location controlled scanning: site location and department location. ("Department" is the new term for what was called "groups" in the 96 scanners).
The RR database has a location (lat/long) for each site/tower along with a "reception" range. There is also a location for each department along with a "reception" range.
Because the MSP is a statewide agency the "reception" range for this department (aka group) is large. The same is true for other statewide entities (BCA, corrections and federal users).
If the range wasn't so massive, someone with a HP series radio using GPS control, would not receive these statewide entities all over the state. That's because as someone travels around Minnesota, the GPS input may cause the department to be "turned off" as it was out of range.
This same principle is applied to other states. For example, Indiana has a similar statewide system. The range for departments (aka groups) is like 165 miles. Here in Kentucky, the statewide conventional system's frequencies show a "reception" range of 228 miles.
I agree that the second link you have is showing a 400 mile circle. However, when doing a download of the Minnesota system, the range for statewide departments comes in at 250 miles. I'm at a loss to figure out the discrepancy.
I hope I'm making sense of this. It's one of those things I think I know how/why it was done, but coming up with a way to articulate it is challenging.