Are you starting fight with 3k tp? cause 3 cdc will range from 30k to 80k and there's no way tizona will come even close.
Isn't 3000 TP Expiacion with Tizona around 15000~18000 too? Which is about the same or a bit higher than avg CDC? So it's actually Tizona v.s 1~2 extra CDC from Colada. If you over TP due to multiple attack proc, you may only get 1 extra CDC out of it, since you don't always WS at exactly 1000 TP.
Unfortunely I can't get spreadsheet to display avg 3000 TP Expiacion damage properly to do precise comparison. Wiki listed the WS 30% STR / 30% INT / 20% DEX mod, but the spreadsheet listed on 1st page only has 2 slots for WS mod.
Just a heads up, the Expiacion FTP value also wasn't correct in spreadsheet, it's different from what's listed on bg-wiki.
Edit: Also just wondering how hard/easy it is to chain CDC light SC without AM3/SAM roll on BLU nowadays. If you can't solo light SC without SAM roll reliably with Colada, that's more DPS lose from SC.