In figuring the NFL's strength of victory tie-breaker, what about teams a team has tied? In other calculations, a tie is counted as half a victory.
No. "Victory" means winning, not tying.
The strength of victory counts only the actual victories, where the team won.
The NFL tiebreaker procedures do not list any alternative definition or calculation for this, so it can be assumed to have the simplest form possible: the combined record of teams beaten, expressed as a winning percentage.
This calculation will count the beaten teams' ties as a half-win, as usual.