Maybe on the scale of five hundred ships, pickets included, would be more reasonable.
Also, something else to consider. Pulse shields deflect projectiles, true, but all torpedoes, and missiles, and most other weapons come equip with proximity warheads that would detonate it anyways when it comes within range of the targeted target. Even those without, most of them would detonate from the force of deflection too.
Plus, even though Pulse Shields are like, 10x more powerful than regular shields, there is still a limit of how much power they can absorb. Basically the shields can make a Claymore have the absorbing capability of a Super Star Destroyer, but even those ships can lose their sheilds with large missile volleys.