I'm glad you liked it :)
I am quite confident the math is right. It's not really that hard. However there are some very clear reasons why people recommend crit damage mods:
The main one, I believe, is obtainability. Jawa are a fairly easy farm: all the Jawas are in stores, except Jawa, who is in a cheap cantina node. Meanwhile, first order has 2! hard node only farms (FOST and FOTP), as well as Kylo on a medium cantina node. That means farming FO is a significantly bigger investment than farming Jawas, and many people have not even unlocked offense mods yet. It also means that most of those who have 3*d the offense challenges, probably 3*d the CD challenges far earlier, and simply have had more time to farm better CD mods. Meaning that a large portion of the players use CD because their best damage mods are CD mods.
Second one, is that many offensive toons actually have the CC to take advantage of CD mods. Toons like JKA, Rey, Wiggs (not to mention Biggs' special guaranteeing crits), Lando, Leia, the IG droids, etc. have a high crit chance, and it only takes a single set bonus and some mediocre secondary CC to take them over that 48% where crit damage wins out (not to mention Han Solo who doesn't even need mods to take him there). And even if you don't quite manage 48%, anywhere between about 40% and 55% crit chance, the damage difference between offense and CD is not very large. Moreover, some teams benefit from "guaranteed crits". For instance, Biggs' special (pretty much) guarantees a crit, Leia and Han Solo give crit chance up to her whole team, Resistance (under Finn), Sith (under Maul) and FO (under Phasma) have Advantage more often than not, and droids get +30% crit chance under an HK lead. This means these teams can count on critting far more often than the toons' native crit chance indicates, easily pushing them over that 48% threshold in actual battle situations.
Finally, people like big numbers. Even if on average, a toon doing 20k basic hits and 36k crits (at 50% crit chance) will do more damage than a toon doing 15k basic hits and 40k crits, people will often think the reverse. There is also an in-game reason for wanting this: there are far more toons that heal (or have life steal) than that rez. And thus the ability to OHKO on a crit (even if it happens rarely) *might* be more useful than sustained damage. This depends heavily on your arena team and playstyle. For instance, the old Wiggs teams banked heavily on being able to one-shot one of the opponent's toons before he could move. The Chaze/Nihilus meta was far more about chipping away slowly and steadily (and taking out key toons with annihilate). The CLS meta seems to be a bit of a mix, but is definitely bringing OHKOs back into the game (especially with AA lead offensive teams). And for OHKOs you want big crits. It doesn't matter whether you leave your target at 50% health or at 2% health: leaving him at any health means your OHKO team failed, so big crits are the name of the game in these teams.
