The best way to explain it is regardless of which individual player you control, any of the others defending a receiver basically plays early 2010s soft ass Iowa zone defense where we sit in a zone and let teams catch the ball in front of us for 5-15 yds every play and THEN try to tackle them afterwards, and the CPU will repeat that until they go down and score.
Every once in a while I would be able to successfully switch players in time so that I could peel off a DB or LB from his robotic electronic football-looking route in coverage to actually come back and, ya know.......try to break up or intercept the pass, but it became such a hit or miss pain staking process that I was just like f*** it. I'll just sim defense until I get back on offense.
There were a few rare occasions where the wonky gameplay would actually have the DB run to a spot and stop in coverage and basically wait for the ball to be thrown to him while the receiver was still running his route, but it was still too much of a mess for me to waste anymore time with it.