Yeah, it's pretty useless for PVE as I read it. It might be all right for PVP if you're loading up on gear with +troops bonuses. But not all artifacts are guaranteed to be useful.
In case you'd like event drop percentages with a larger sample size, now that I've cleared the end boss 1500 times, I got 13 soul tickets, 16 SSR Takeda Shingen cards, and about 9500 souls. That's all in line with the percentages I gave above. If you want a larger sample size than that, you'll have to get TruelyNice to post here and hope he kept statistics, as he's already beaten the boss over 4000 times.
The event ranking is that you get 40824.7 points per time that you beat the end boss. I have no idea why it's that exact number as opposed to some other, as the boss has 398247 troops in total. It's probably a glitch of some sort. But if you want to know how many times someone else has beaten it, some simple arithmetic will tell you for anyone on the top 50.
For what it's worth, the point of the gear drops is not because they expect you to actually want the gear. It's to fill up your inventory and force you to go clear it out. That makes the event harder to macro.