Most, if not all, players have default trigger movements, and more often than not, when they're struggling (or nervous - see even TPC in his first 15-20 balls) those movements get exaggerated. Unfortunately for Bancroft, his trigger movement is a biggish step forward and across with his front foot. Because he's struggling, the movement is more pronounced than when he's in form, and it's also heavier, because he's planting the foot and feeling for the ball instead of moving into it. As a result he's having to play around his front pad all the time, even when he wants to play straight, and his bat is coming down at an angle instead of straight. It's almost the opposite of Warner, who's feeling for the ball by going across the crease instead of making a big step (forward or back) and is getting caught on the crease.
What gets me with Bancroft in particular, is there are about 842 support staff and coaches with any given international side, and it seems none of them have thought to work on his trigger movement with him. No evidence at all that they've looked to modify it or to take some steps with him to minimize the size of the step he's putting in. These aren't actually massive deals to fix,. particularly given the amount of cricket and practice these blokes play.
Warner is just out of nick and feeling for the ball instead of having his head still. Bancroft is basically displaying a Gooch 1989 technique, which in this day and age I find incredible given how easy it is to spot and to work on.
Long story short, no I wouldn't stick with him, but the team management will because they seem blind to the obvious fault in his technique.
