Augusta final nuke damage with verdant summit

My Augusta (S2) with verdant summit final nuke hits around 295k against Fleurdelys middle TOA. I used ele/att for my 3cost as i have lower nuke around 280k with double ele.

I tried comparing my damage with other S2 in showcase videos. With almost similar stats as me the only difference is sig vs verdant summit, the person hits 350k in the same TOA.

Is is just the difference of having sig or am I missing something. I tried similar rotations as recommended Youtubers.

https://preview.redd.it/1gt2jugmy8mf1.jpg?width=1920&format=pjpg&auto=webp&s=d43bf2b1707fd0d929766b7961714de6ebeb16aa

https://preview.redd.it/o41mr7ymy8mf1.jpg?width=1920&format=pjpg&auto=webp&s=bdeeca783bb77d5a178197a9bdcd864f00328ba8