Trump wants 15,000 more agents on the southern border. The border is 2,000 miles. That means there would be 18 agents for ever mile of border or an agent for every 290 feet. This seems like a big overkill when you consider the difficulty in crossing large portions of the border and the technology we have available today to detect and track intruders.
What a dumbass! You think those agents work 24/7/365?
Of course not. If you allow for 3 shifts it's 6 agents per mile per shift. Round the figure down for sick time and you're down to 5 agents per mile per shift. That's an agent every thousand feet.
No one has pointed why we need that number of agents. When most people think of the border and the patrolling of the border they think of a border fence with a road running beside it. However, in most cases that road is many miles from the border, as much as 50 miles. So when migrants cross the border, they may go in many different directions making apprehension very difficult if not impossible.
The solution is really very simple. Build a paved road as near the border as possible so agents can be at a point of intrusion in minutes, not hours. Second, use technology to monitor the border and track intruders. We would probably need a lot less agents and apprehend a lot more people. Also, we would save the lives of lot of people that get lost out the desert.