Against bottom half teams, start Williams/Greenwood and go a lopsided 442. You have the fast wingers to help stop the counter attacks that are going to start deep in their half providing you keep executing properly.
Absolutely bizarre that he doesn't line-up more attacking/rotate against bottom half teams. If you lose while taking a gamble you actually win in other areas and these effects can be leveraged over an entire season.
Also, you rotate to keep players motivated: if the 'weak' side draws/loses, then the next game you use that to get the more 'senior' side to work harder to pick them up; you also raise morale by showing trust in those younger players - wins with those games pay off tenfold, the list goes on and on.