April 14, 2018
As you get further into this game you'll notice the bottlenecks.
There is no way to build troops so gem buys are about the only way to get there. In my estimate, it would cost around $2,600 to get five 4* troops to max level without catching deals to lower their prices. (other than the 10 troops for 1,600 gems) That doesn't take into account the food costs either. To level up a level 13 troop it's 77k in food per.
1* = 40
2* = 90
3* = 200
4* = 400 (If you spent the $2,600 you'd likely have enough to do this but you'll notice you don't get the 10% bonus in exp going from 3 to 4* like you do with the others, you just get double)
Once you get your heroes you have to feed other heroes too them. The most efficient way to do this is to have a level 11 TCs running "Extra-low cost" heroes full time. While 8.7 is the best place to farm recruits, it's not the best place to get backpacks 5.8 does that. Backpacks allow you to do "uncommon" for 2k in food, 5 recruits, and 1 Adventurer's kit. This is your best choice, but you won't be able to farm enough backpacks to keep a TC running this full time so you have to swap back to "Extra-low cost" when you run out of backpacks. And of course, once you get a TC to level 20 you'll be running the Legendary to try and fill in the holes you have with some new 5* heroes. That's a whole nother beast in and of itself. Here is a link to the 5% drop rates of 5* heroes from a level 20 TC:
For tier 3 on the 5* and tier 4 on the 4* these items are going to be the pain point:
- Hidden Blades Fire
- Orbs of Magic Holy
- Trap Tools Dark
- Warm Cape Ice
- Sturdy Shields Nature
For tier 4 on the 5* these items are going to be the pain points:
- Mystic Rings Fire
- Poison Darts Holy
- Royal Tabard Dark
- Farsight Telescope Ice
- Mysterious Tonics Nature
Your main source to get them is Titans. Here is a link to the guide where I got the information but getting loot tier 9 is really the only thing that's important because that gets you 3 rolls. So if you are killing titans 9* or better all you need to do is 1% of the Titans total hit points to get your 3 rolls. If you are killing an 8* Titan you need to do at least 3.3% of the total titan hit points (B) to get your three rolls. If you are fighting a 7* you need to be in one of the top 5 damage spots, and if you are fighting a 6* you have to have the top damage spot to get all 3 of your rolls.
Feeding heroes vs keeping heroes:
One more thing. As you decide to keep your heroes or feed them to other heroes keep in mind that there are events that require you to use 4* and 3* teams. For Events, Titans, Raids, and Alliance Wars you will most likely want to color stack at least a little so you need to be able to swap out heroes. Alliance wars require you to have 6 teams (they can all be 5*) to be the most effective, and invariably Empires and Puzzles is going to nerf/balance certain heroes so think hard before you use a 5* hero to feed another hero rather than waiting.
Here is my current main team.