I would put smith there and give moon a chance at 6

I reckon keep Smith and Holdsworth together for the time being, think they need a bit more time to gel properly. It could give Owen a real chance to shine, or we could stick to Howarth. If it starts going wrong then try Smith at 9 and something different with the halves, maybe Moon at 6 even.

Why are people saying that the Holdsworth/Smith partnership needs time to "bed in"? Didnt they play together almost all last season?

To be fair Smith spent a lot of last season also being our 2nd hooker. So you could (weakly) argue that they have n't really had a proper chance to gel

You're right, it's a very weak argument!!
FWIW I thought we did OK defensively on Saturday but for all the good things Howarth did we missed Godwin's speed around the play the ball. I would definitely give Owen some game-time as his replacement. Saints away = certain heavy defeat anyway so why not throw him into that game?