When hand picking his Omega Force he skipped over one of Starfleets experts on the Borg collective "Icheb".
Not only is Icheb a former borg drone, he was bio-engineered by his parents to fight the borg.
He can never be assimilated again since it would destroy what every part of the collecitve he was with because of his genetics.
Seven of Nine even told him that he would one day fight the Borg but in his own way.
But we find him at Club K7 drinking the days away giving out PvP missions and being annoyed that Wildman out ranks him.
Give the guy a promotion and move him to Omega Force, have him trade postings with Commander Roxy, or just have him stand next to her for now. Maybe for "Into the Hive" we get some help from then Command Icheb...sounds good to me.