It won't be max if the stats' IVS aren't at 31. The personality only shows you the highest IV on your Pokemon. When you're breeding for multiple IV Pokemon, the personality doesn't matter very much because when more than one IV is the highest at 31, it'll choose one saying at random for the personality. So it could say "Likes to Run", but it could have the same IVS in Speed (which the personality tells us) and any other stat,such as HP.
So no, the personality doesn't matter. You want max speed and attack on your Druddigon? Try looking for a 6IV Ditto. Give it the Destiny knot, and it'll have a higher chance to pass it's good IVS to the baby Druddigon when bred. When your Druddigon has better IVS than the one you originally had, put that one in with the Ditto (give them an everstone so they'll always be Adamant). Keep doing that until the IV rater tells you all the stats you want "can't be beat", which is the best (31).