Always remember that public safety communications has very little to do with common sense, or interoperability, and very much to do with local control and politics, due to lack of subject matter experts in key positions, and LOTS personal insecurities. Regarding Lubbock, or even midland would you tie your little bitty system into someone else's core for the cost of a lease circuit, when you can spend a few million more and have VIDA core?? Hell I bet they even bought 2 cores for redundancy. It's all about local control.
As long as stupid decisions continue to be rewarded with grant money, this will never, ever, change. Even if this radio system was bought with budget dollars, the fact that they made this stupid decision that puts their heads in the sand should prevent them from getting say a body camera grant, or something else. Hundreds of millions, if not billions of dollars of land locked P25 systems across the state, some overlapping each-other, all have received grant funding at some point to support those systems.