Malignance also has it's strengths: You can haste cap without needing to sacrifice other slots, the STP stat synergizes better with Tizona aftermath and afaik (you read different opinions here) is still BLUs strongest WS option with the exception of self SCing with Prime while soloing. I'm not sure if MP sustain is a issue with prime but with Tizona it isn't in most situations so you also save spell points that you'd otherwise need to invest in for example battery charge.
Without any other sources of multi attack Tizona aftermath (40%/20%) would cause 40 out of 100 hits to be double attack and 20 to be triple attack.
If you add the 34% triple attack from sworn you'd look at:
34% (sworn triple attack) out of 100 hits = 34 triple attack leaves 66 attacks
20% (occ. attacks thrice) out of 66 attacks = ~13 hits (floored) leaves 53 attacks
40% (occ. attacks twice) out of 53 attacks = ~21 hits (floored)
so in the above example you'd sacrifice 7% triple and 19% double attack from Tizona aftermath if I'm not mistaken.
I guess if max damage is your first priority, you have a prime sword, TP feed and MP sustain are no concern then the new limbus set is most likely going to be the best choice, at least while soloing but maybe also in party situations.
At the end it will be situational.