When one of the players you did a 4-man Ttar raid with...
Happens to be the same guy who spent an hour taking down your gym while you are remote feeding, 30 minutes ago.
Yes, this just happened to me.
I have never met that guy before today, even though he lives nearby. There are just so many players in Singapore!
Also, this was my first 4-man Ttar raid! I admit it was done in cloudy weather, but still very satisfying, considering most players here are not willing to try Ttar with "so few players". And none of us were above L35.
My team was 1 L30 C/DP Machamp, 2 L30+ C/DP Hariyamas (with mediocre IVs), 1 L32 DT/O Dnite, and 2 L30 AT Vaporeons. Ttar moveset was IT/FB. We did it with 18 seconds left, which is still quite good, because the other 2 weren't using optimal counters.
Answers
It's funny, the Instinct guy who kicked me out of my gyms in the local park and then asked me for help in an Alakazam raid (he was embarrassed, but I just said thanks for the coins) gave me the best gift a rural player can get: an invite to the city Discord, which has led to the ability to do legendary raids (and, so far, Suicune, Groudon and an EX-raid pass).
The new gym system has done much to reduce inter-team hostilities (but a few people still get carried away....)
Congratulations! If you optimize your team a little, and find two more mid-30 level players, you'll find that three-manning it is very doable. Back in August, my daughter and I did it with a friend, succeeding on the fourth try. I was level 38 at the time, my daughter was 32 or 33, and the other guy was 33 or 34. At the time, I only had two Machamps, one with C/DP, and an old KC/Crosschop one, so I had to fill out my lineup with a Dragonite, a couple of fighting Poliwraths, and a rock smash Rhydon (to the best of my recollection). We were fortunate with the T-tar's moveset (B/C), which is one of the easiest to beat. To this day, it remains one of my favorite raid achievements.
Now, with three level 30-32 C/DP Machamps and a level 31 C/DP Hariyama, according to Pokebattler, I should be able to do about 50% of the required damage against "unknown moveset," meaning that I could two-man it if I find someone else with an equivalent team. And it's not like my Machamps are 100% level 40's or anything.
I guess my point is that every additional C/DP Machamp or Hariyama you can acquire will greatly increase the damage you can inflict on T-tar. C/CC isn't nearly as good, but is better than just about anything else. And C/DP 'Champs are good to have in a lot of other scenarios as well. They might be the most important mons to have in the game right now. In the meantime, if you want to prepare for three-manning it, exploiting the double weakness to fighting is key, so double-fighting Poliwraths and Ursarings will far outperform your Dragonite and Vaporeons.
I predict it won't be long before you are telling us about doing a successful three-man T-tar raid.