I finally finished the event! (Well, cleared the 142k mark for the tanks... After spending 750 cores for bat and ghost wings... )
So I take the new tanks out for a spin and drop the M3 into play. I activate her haste right as my front line is breaking up. She slams into the side of a threadbare enemy artillery, claws her way through it and then shoots off -sideways- on this weird goddamn golden ratio curve of a decaying orbit that takes her directly BEHIND the enemy commander. So I'm out of just about everything and the enemy is still sending out a column of Tigers to stomp my Lt. into gravy, while the M3 just hangs out and stabs the enemy commander in the spine. The enemy commander still has a LOT of health and I'm about to be overrun so I deploy my last tank right as the enemy stomp squad arrives and drop a defender buff on them, giving the M3 just barely enough time to finish off the enemy commander.
And that's how I beat the third event tile too late for it to do any good.
(Stands up. Uninstalls browser. Lights computer on fire. Jumps out window.)
Hail Satan.
It probably wasn't their intention that the golden tickets from this event would convince me that the wishing wheel is utterly, hilariously worthless but they did and I am. A 100 cores a spin when getting 150 oil or 1000 coin is not only a possibility but a practical certainty is something I can't even laugh at. The sane underhanded approach would be to have every section of the wheel be at least 'value equivalent to the cost' and only then introduce skew drop statistics, marking only some specific and less useful things within a category drop commonly.* You should NEVER make it THIS apparent how and where you're cost-value screwing people with a gacha if you want them to spend on it.
* Basically, fill your machine with fifty Dave Guys to one Ranger Guy. Slow fat children will spend heavily if they feel they're 'so close' to getting what they want.
Also sunk cost fallacy. Psychology. Use it.