Every other team rotates their hookers.
The fact that Alker is either too stubborn or thinks he is better than the replacements to take himself off is having a detremental effect on the team.
McRae is also obviously too weak to tell him this.
Why he was made assistant coach I will never know

Alker 2nd row with Adamson, Swain at loose. Which then means both smiths can rotate at hooker which will add speed and we still have alkers defense in the team because lets face it we don't have him in it for his passing and speed attributes.