Too big of a damage difference?

I play an SMG Siren. I have a few skills:

• 7/5 Accelerate which gives me 21% more gun damage
• 5/5 Reaper which gives me 40% more gun damage on enemy's health above 50%
• Cat Mod which gives me 71% more SMG damage.

I have two SMGs:

and

The damage difference between both is nullable, as the other bonuses. The only difference is the element. Even though, I hit around 4-5k with the Slag one, and around 2-2.5k with the Shock one. These damages are done on Normal playthrough on Flesh enemies.

Seen this table of element, both Shock and Slag deal 1 on Flesh.

I don't have any boost to Slag damage, nor Tediore weapons. Am I missing something?