As a tool to select your best team I created a spreadsheet with all troops.
Currently you can filter on the following fields:
Class / From: Create a custom filter to select e.g. a kingdom or all legendary troops
Name: Name of The Troop
Level: Skill level of troop
Life: # of life for each level
Attack: # of Attack for each level
Armor: # of Armor for each level
Magic: # of Magic for each level
HP: # of Hitpoints for each level (Life+Armor=Hitpoints)
Cost: # How much it cost to release the Troop Skill (if you like fast teams filter only 6 - 9)
HP/COST: Will give you a ratio of how much it cost vs #HP (The higher the better)
Colors: Color filters to select e.g. only the troops who need red
There are some filters already added like Class, Kingdom and Skills (extra turn). Not all filters might work properly as I have not checked all of them but you can simply create your own custom filter by clicking on the filter icon on the top left corner.
The best way to start is to select only Level 15 and filter out the rest of the values.
Have fun and feel free to ask questions in case you are stuck.
Spreadsheet updated 2015.10.16