The set up you want to aim for + skills you want to do in the beginning is the following:
Leader - Highest Speed Aura - You Have Access To <---------------------------------------High Khatun - 19%
1st move - Team Turn Meter Filler + Speed Buffer <------------------------------------------High Khatun
2nd move - Team Increase Attack 50% <---------------------------------------------------------You don't seem to have one
3rd move - AOE Decrease Enemy Defense 60% & Weaken 25% <-----------------------Zargala or War Maiden
4th move - AOE Damage Dealer <------------------------------------------------------------------Galek or War Mother
Zargala & War Maiden are both used for the same thing.
You only need to use 1 of them.
Zargala is better because she hits a lot harder vs. War Maiden.
Zargala can kill heroes with the damage she does.
However, Zargala & War Maiden are not really long term heroes.
War Maiden is a Beginner hero ---> Rare Hero
Zargaala is a Intermediate hero ---> Epic Hero
Long Term Hero -----------------------> Legendary Hero
Zargala & War Maiden apply Decrease Enemy Defense, but they don't apply Weaken.
Long Term Hero - You will have will probably be Rhazin - Fuse able at the Summoning Portal
Rhazin does both Def Down 60% + Weaken 25%.
People still use Zargala in some of the higher stages of Dungeons & Zargala is seen a lot in Gold Tier Arena's
However, Rhazin is a King in Dungeons & Arena, too!
Using Zargala over War Maiden will elevate your team over all damage vs. players who are forced to use War Maiden because they didn't get any good shard pulls.
However, you can still progress with out a Zargala.
I don't have a Zargala - I fused Rhazin.
My Rhazin will tier a Zargala Apart by himself.
So again use the Hero you are most comfortable with.
Galek & War Mother are Damage Dealing Attackers.
Your Galek is level 60 + Fully Ascended + Fully Booked - It stands to reason you should use him
Your Galek in his current state can probably do more damage vs. War Mother in her current state.
The game gave War Mother a buff.
War Mother as 100% Chance to place Attack Down 50%.
I don't know your Clan Boss Situation.
However, most players run Attack Down heroes in Clan Boss.
If you don't have a hero which does Attack Down to the Clan Boss, You are probably going to have to 6 star War Mother for your team.
This would mean your War Mother will probably get to level 60 + Full Ascension + Fully Booked.
Most heroes used in Clan Boss need to be Fully Tome - So yeah
Long Term - Your War Mother might dish out more pain vs. Galek.
You will simply have to monitor the Damage numbers your War Mother does in comparison to Galek.
All that matters is who does the most damage
Your Damage Dealer in Arena is the Hero who is going to annihilate the enemy team in a single blow.
You don't care what Rarity the hero is.
You don't care what Faction the hero is.
All you care about is picking the hero who Destroys the Enemy Team better!
You just want to make 100% sure - They are dropping people like a bad habit.
- Crit Rate 100%
- Crit Damage 200%+
- Atk % 4k+
In Regard to your statements about Skill Tomes!
The only Skill you want on High Khatun to be booked is her A2 - Turn Meter Skill
The other skills don't matter because you are not planning to use them.
The only Skill you want on Zargala to be booked are her A2 & A3 - The Decrease Enemy Defense Skill
The A2 unlocks the A3.
You want the A2 to hit really hard + have a low cool down
You want the A3 to have increased 25% chance of placing Decrease Enemy Defense.
The other skills don't matter.
The only Skill you want on War Maiden to be booked is her A3 - The Decrease Enemy Defense Skill
The other skills don't matter - You are only using her for 1 move.
Galek & War Mother are Damage Dealers.
You normally book your Damage Dealers to max so they can get increased Damage Percentages to hit like a Truck.
Should you book War Mother?
Well that decision is up to you.
I WOULD NEVER USE WAR MOTHER!
Just look at War Mother - She is massively overweight for her size.
Just look at War Mother - Insects are flying around her - Total Lack of Personal Hygiene.
War Mother is nothing more to me than a Smelly, Fat 5 Star Chicken.
It is fitting that War Mother places "Bombs" because she is a ticking Time Bomb herself.
War Mother is 1 Sandwich away from having a Heart Attack.
I can't be bothered login every day to see such a character on my account.
War Mother represents the growing obesity problem in the United States.
I don't care if she is a Legendary or not.
I'm not using her.
If you want to use her, Go ahead.
You do you!