I feared Kash in the beginning, now with my 2/2/1 holy/green/blue team i could not care less, actually im pretty thankfull for every healer in the tank position.
Free Specials yeah!
I would do scarlett-kiril-kash-tiburtus-chao if you want to use Kash.
I fear Lixiu way more and would try Boldtusk-Rigard-Li-caed-triton when not using kash.
That is exactly why I would surround Kash with Triton and Kiril. They would be red invoulnerable… Stacking reds would be usless…
I would set Kiril-Chao-Kashhrek-Wilbur-Proteus if I was to setup a Rainbow team.
Nice.
Although my other pairings with Kashrek are totally different from yours. 
I think with what I’m working with, this is fine. I don’t think you mentioned any ideas with kashrek tank btw, just that you use him
My current defense is
Zim - Alasie - Kashrek - Magni - Azlar
Thinking about:
Rigard / Grimm / Kashrek / ? / Richard
The question is: Inari - not finished, Proteus, Chao or Little John.
What’s Four opinion?
I would put:
Rigard - Grimm - Kashrek - Richard - LJ
I have Tiburtus - Kiril - Kashrek - Magni - Marjana.
Marjana only 3.70 so I plan to replace her with Zeline once I finish her. These 3 guys in the middle hold up very well, handled many war attacks when the 2 in the back were already down.
Why LJ at the edge? He is slow so I fear that it would last to long until his special effect can start?
My concept of playing is that right wing is usually occupied by an AOE finisher. The other 2 does little impact late in the raid.
Is there any reason to put Rigard in the left and not the right corner ?
I am thinking about the following set up.
? - Kiril - K - Sonja - ?
Contenders for questionmarks:
Yellow: Chao, Wu Kong
Red : Scarlett, Colen
Purple: Tiburtus, Proteus
I could switch Sonja with Boril but the I have no dispeller.
Skills are launched from left to right by the AI.
Always heal/cleanse your own team and dispel/debuff the opponents buff before other damaging skills.
So definitely Rigard has to be on the left to cleanse your team of any attack debuff that you may have.
My suggestion
Kiril - Tibertus - Kashrek - Sonya - Colen
I never liked Wu or Chao at defense to begin with. Wu makes your team miss attacks and Chao does not have enough firepower to be an effective sniper. His mana control is only 1 target which the AI can be stupid to fire at the wrong enemy.
Excluding K and the skills fired from left to right:
Kiril - buffs your team
Tibs - defense debuffs the enemy
Sonya - dispels and any other buffs the enemy have have
Colen - for the finish
So you prefer Tiburtus to Proteus. Interesting.
Of course you are right with Rigard.
I think I prefer Kiril in the left flank and Tiburtus on the wing because of coulour sysnergy with K.
Do you think Colen will ever fire in the right wing ?
Scarlett has high tile damage to and debuffs 3 attackkers and is fast.
Kiril in the left wing to buff your teams offense.
Colen is your gamble card on the right wing. Win or lose will depend on him. Right wings battle when your middle 3 are dead most of the time. Do you think Scarlett can change the tides? Most likely not. Colen can.
Yes Colen can change the tide but Scarlett may not make it necessary to change the tide.
Will have to test it. 
Dont you think to flank K. with 2 blues is better than to flank him with 1 blue and 1 purple.
The blues that flank K has to impact the fight. Kiril is good at buffing but strikes no fear and wastes K’s healing. K is to stall for time for strikers to hit. Not do extra healing and buffing.
To add on what it means to put fear. I flank K with Alasie and Magni.
Alasie is the single highest hit sniper in the game and gives 5% offensive elemental link so she is left flank with Magni on the right (who is also a top 3 sniper) with an added 5% attack bonus. Do you think anyone wants to have both of these blues to fire?
I understand that not everyone has both of these heroes thats why I gave you the recommended lineup. Scarlett is better used for offense and Colen can be used on both ends. For a 4*, he is one of the tide changers which is similar to the Azlar that I always like to use on the right wing.
If you really want to use Scarlett, she is better as flank rather than a wing.
Lately I have done some levelling work and now run the following for my war defense:
Rigard (max) - Inari (4-70+)- Kashhy (max) - Magni (4-40+)- Gravy (3-70)
I have enough mats to ascend a dark hero and 2 obakans sitting there waiting, but Rigard is so sticky in that left wing, wasting people’s flags every war that I am loathe to replace him with anything other than a stellar purple. is obakan worth it? I don’t think so.
Inari is a controversial choice, but my holy slot is tricky. I have Wu and jackal maxed, and Gretel is a hair away from max now so maybe she is better in this particular case, adding more teeth to the defense. I did get lucky with onatel from a token but I am a long, long way from my next set of darts.
Magni’s spot is uncontested right now. I miss a pulverizer but my troops favour a rainbow defense. Is pulverizer worth subbing out Magni for Grimm?
Gravy is there in weakened form because my only other fire options are BT and Wilbur. Hidden blades are the rarest ascension mats aside from gloves, apparently!
Edit: so I still don’t have the update but apparently the lizard is a wizard. Sounds tanky? 
I have no 5* heroes, so this may help folks in a similar spot.
For a long time, I was using what were my first 4* heroes, and it worked reasonably well, admittedly, I got pretty lucky with the RNG, at least I thought I did:
Proteus-Kashhrek-Boril-Colen-Wu Kong
I since got Boldtusk, and have now tweaked it to this, although Boldtusk isn’t maxed quite yet:
Proteus-Kashhrek-Boldtusk- Boril-Wu Kong
