If the seals are close enough to overlap the first one to go off destroys the others and all we get is a single TN 40 blast to dodge. If they're not overlapping, then we get many TN 40s to dodge.Or just fistfuls of explosive seals! Unlike the Railgun the Arty Rune is kinder on its projectiles, so the seals are likely to make it to their intended target intact.