As a fellow mono-user, I have my strongest monochrome team I use whenever I battle certain teams in raids. But I have at least 2 monoteams per element for wars. If I find the war enemy to have blue tanks, I would split my entire green roster of heroes and form at least 2 monogreen teams that are as balanced as I can get. In my case, my first team is composed of Albe, 1st Eve, 1st Lianna, Gregorion (supported by a level 17 mana troop so he can fire in 9 tiles) and 1st Hansel while the second team is composed of Mother North, 2nd Eve (3/70 only as I cannot yet justify using any of my 20 tonics on her since Almur is just around the corner), 2nd Lianna costumed version, Buddy (has good minion synergy with MoNo due to family bonus and is supported by a level 17 mana troop so he can fire in 9 tiles) and 2nd Hansel. While some heroes there are emblemed, 2nd Eve is not maxed, but MoNo’s high chance of reviving her makes sense why such team up was made. Sometimes, I shake the members up and include any of my 2 Melendors with costume or 2 Caedmons with costume, or any of my 3/70 legendaries (Atomos, Ratatoskr, Zocc, Lady Locke, Elkanen, Kadilen, Horghall - yeah, I am sitting on 20 tonics). I just don’t think its right in wars to split your green roster to two teams where one is weak while the other is strong. My strategy is to somehow balance them accordingly.
On very fast wars, they say mono is not as effective. A BIG LOL. It is already at an advantage. All I need to do is to make sure I match two 3-tile matches and they are lit, even my slow revivers. Since very fast raid tourneys were introduced, I was already building up several mana troops to level 11. I have not completed all 5 mana troops to level 11 yet per element, but it is getting close already. I can force my hoarded 3* troops to be fed to my mana troops to get them to that level at the cost of my hoarded food in my TC20. In your case, you can support your main heroes in your monogreen team setup by your level 11 or higher mana troops.
Among your heroes, your snipers (Greg and Lianna) should be on separate teams but equally distribute your AOE and support heroes. Costumed Kadilen and your Bertila could be split. Heimdall and LoL (please give her emblems for Pete’s sake) could also be split since their main function is to heal. Don’t just build a team based on one hero. I would also would ascend a second Kad and costume so that each of your monogreen teams would benefit from her support.