I agree (that it is self defeating to try to pursue and promote one idea over another)...the successful solution is a multi-solution approach, pursuing and developing all the solutions simultaneously: a border wall, military, punishment for employing illegal aliens, removing taxpayer funded supports/"rewards" for illegal aliens in the U.S., correcting the "anchor baby" misapplication of the 14th Amendment, deportations of illegal aliens, a huge invoice to Mexico for social services in the U.S. used already by Mexican citizens in the U.S. illegally...all of it.
And no Guest Worker programs, none, whatsoever, until AFTER these conditions are resolved. THEN assess whether or not the U.S. has to import unskilled labor and not employ Americans first.
How does "the U.S." assess this? Doesn't the current situation suggest that "the U.S." has already done so?
It appears that what you're really suggesting is the "the U.S. Government" needs to assess it, and that "the U.S. Government" will decide on whether or not to import labor.
There are reasonable arguments for and against this; my point is simply that your suggestion is basically a call for government involvement in the labor market.