Just stats from cruzz spreadsheet. You can simply calculate it yourself and you will get the same results.
As an exmaple:
Firefly against P4: It takes 4 hits to destroy the P4 because 4x200=800 HP and P4 has 640. There is no reload on the first shot so it´s 3x reload at 8 seconds = 24 seconds.
Things are a bit more complicated since there also time to aim and wind up wind down and not only reload.
On the other hand you still do not calculate Tulips or the fact that FF once vetted can kill a medium with 3 shots instead of 4.
In addition FF is a T3 TD with less tech cost.
In the end of the day do UKF need a stronger TD? It does not seem so since they have great ATG, great hand held AT and many other AT assets.