Again, them having any normal sabots is supreme PIS, not having a supply chain or ammo depot present even moreso, like they just waltzed in and started shooting without thinking, durr, we might need to reload and refuel at some point, this is CONUS, they have normal bases within driving distances. Brooks basically just took the old joke about old generals and latched onto it as his entire justification for the scene with no regard whatsoever for actual doctrine(and I'm not talking about some half hearted wire, I'm talking about properly set up triple Concertina Coils, which when set up properly can stop tanks dead in their tracks).
And I don't believe Cap gets tired, or at least not the way a normal human does, keep in mind Cap 2 opened with him running 13 miles in half an hour(to put this in perspective that comes to about 3 minutes 15 seconds per mile, the world record for a single mile is 3 minutes 43 seconds), which is essentially a non stop dead sprint without ever slowing down, and he was barely breathing hard