Tab rake is not a punishment be happy you can keep your CP's when you do it.
why would you compare rake to shred then to swipe? your numbers are way off because you did not work in the energy component. Swipe is 45 energy rake is 35
For each feral the swipe limit will be different and based on gear. The more mastery you have the higher target threshold before you swipe.
Doing a pug while I post this thread so these numbers are taken from trash.
rake
54,000 damage
1543 damage per energy
swipe
8,000 damage per target
178 damage per energy
To figure out your swipe threshold
1543/178=9
so you need 9 targets within an 8 yard radius to swipe. Need 18 targets during incarnation (should save inc if this is the case anyway)
Please do not post information if it's not valid. Some poor feral would read your post and believe it.