Why would you consider a deck that is such a small portion of the field? Also, your assertion that you auto-lose to them without Sage is wrong. I'd say that most of the games you lose to them are games in which Sage would do nothing since they either win or lock you out of casting spells very quickly.
The last time I played against Metalworker my opp was on the play game 1 and curved Chalice on 1-Trinisphere with T4 Forgemaster holding Lightning Greaves. He didn't take a fifth turn. I cast a Zenith that likely could've found Rec Sage but it was irrelevant, any elf was good enough with Natural Order.

