Honestly like in real life it is generally a good move unless you got a real beast as a back ala mike alstot....Just like in real life when a back gets to the next level and goes up against a LB 50+ lbs more and can not get around him the best move is to go down and preverse there body/fumbling from a big hit. try to take that guy on and 99/100 times your not going to run trough him but get yourself blown up injured/fumbled....dance around too much or get stood up and then another defender will blind side you and blow you up!
Its very realistic to go down that way.