4.1 WAR as a leadoff man with un less juiced ball is about all we might expect. WAR doesn't care where you bat in the order and the de-juiced ball applies to everyone, not just Bryant. if anything, you could argue that hitting leadoff would allow him to accrue SLIGHTLY more WAR by function of the marginally higher plate appearances/opportunities. it's fairly negligible compared to his previous spot in the order, of course. and that's without even getting into the juiced ball part, where it's arguable that the juiced ball affected different players in different ways and may have actually hurt some players more than it helped them relative to the rest of the league.