2000 miles divided by 8 prototypes. I suspect they would ALL do fine compared to what’s in place now, so that’s only 250 miles per wall. I say award every one of them 250 miles and just see how they all work - testing while on the job.
There will be so much money saved by not paying for the illegals stopped, no need to worry about replacing a section or two down the road.
A guard tower with machine guns every 1/2 mile would increase the reliability. 4 guys on rotating shifts per tower is only 16,000 patrol officers. ICE already has 20,000 employees. Put them all on the border. Better yet, put them all on the border until the wall is actually built.