Police and sheriffs are local costs and the state does not fund those ops.
National Guard are not limited by posse comitatus (unless federalized), and can be legally used for maintenance of social order, as well as repelling invasion.
Guard is funded by the sate and can be deployed to patrol the border (deter and report), and if attacked, fight back.
You may feel this is a political stunt. I think not.
What I find disgusting, since you used the word, is people demanding all-out action but not recognizing funding issues or legal limitations, but demanding action nonetheless, and when action is taken taken, within the Texas constitution’s balanced budget requirement, accusing it of being a ‘stunt.’
Pay to keep them out or pay to keep them, your choice.