Thusday-Friendly is the Faction with over 200 in rating, so it can be finish all reward stages at Level 80 without spending gems.
Tinker Town, with 3 Treasure rooms, 2 Ultra-Rare, 1 Legendary, 1 Rare, gave out the rating of 198.32, so one Tier is always needed, unless you got very lucky, which is unlikely.
Rating was calculated by doing a theoretical run at Level 1 with the best path, using average of all rooms types as data. Here it’s usually S-ULT-UT-RT-B, or left-middle-right.
As the floor part is static, the formula can be changed to (20+30+…+80) * 200 = 350 * 200 = 70,000, the required point. So if the theoretical run for avarage fall below 200, you have to play Level 90, thus needing to spend gems.
Also, I really want to try this team soon, as we finally have all 6 Color Captains : troops that give +1 to all stats to all troop of one color on every turn!
Hero can also be Essence of Evil on top, I guess.