Long story short: I started playing in January this year, and classic 4* tanks like Kash, Boril or Cyprian showed up so late that I’m well into Platinum now (2000-2200 cups) and hope to be moving on to maxing my first 5* rainbow to the last tier when the mats show up. At this point, I plan to use the following set-up for my first 5* rainbow defense: Musashi - Kadilen - Frida - Red Hood - Sartana.
In the meantime, I’ve been levelling 4* to get a decent war pool, and plan to max 20 4* (4 each colour) and bring 10 4* to 3/60. My focus is on war and raid offense.
With those things in mind, should I bother levelling 4* tanks unless they’re useful for offense (such as Gadeirus, Boril and Cyprian, but unlike Kashrek).