Please forgive me if I am saying things which you already know. Please correct me if I am saying things that are wrong.

I was told by another player that the battle calculation consists of two parts

The attack - Attacker's troops (with factors for offense and health) vs defender's troops (with factors for defense and health) - this determines the number of troops the attacker kills

The response - Attacker's troops (with factors for defense and health) vs defender's remaining troops (with factors for offense and health) - this determines the number of troops the defender kills

The winner is the one that kills 80% of the enemy force.

If this is true then having 2 health gems (troop specific and enhanced) and 2 offense gems (troop specific and army) would mean your troops would kill more of the enemy (as long as there are more that can be killed) compared to 1 health gem and 1 defense gem.

The real question though is in the response side - Do health and defense just add together? In that case, it shouldn't matter if you have two health gems or 1 health and 1 defense because the total should be the same. If they don't add or they have different weightings then the situation is unclear. This of course applies not just to gems but to the whole balance of health and defense, as long as my original informant was correct.

It should be possible to test various scenarios as long as you can find a willing target who will provide a fixed number of troops with unchanging offense, defense and health and replace them to that number as needed. I have not done this.

Excellent contribution to the thread - thank you!

> attack - ...

that is my understanding as well.

> Response - ...

It had not occurred to me that there would be 2 phases: attack, and counter-attack. Interesting. The idea feels right / consistent. Thank you!

> kills 80%

Yep. Thus the last question posed, really, of the OP, is if you can kill 80% from the get go, there is less to be counter-attacked with. [Does the 2nd Health let you kill so many more than would be preserved if it were Defense instead.]

> ... The real question though is in the response side ...

My understanding / rumour / hints from the ether is that the defense 'value' is of the form x = H/(1+D).

[Or perhaps /(1-.d%), where d is some % combination of the various defense values.]

Thus increases in Health have a multiplicative (?) impact upon the result, while increases in Defense have a much less significant impact. (Thus the OP of 2 H instead of 1H + 1D.)

I have been basing my impressions upon https://plarium.com/forum/en/throne-kingdom-at-war/599_fan-guides/124393_throne-battle-mechanics-1-0--seeking-volunteers-to-validate-data-and-enter-additional-data-points-/, which albeit won't be exactly correct (only reading Plarium's code would provide that), feels correct in overall / approach / intent. [And seems consistent with what I have read on Viking's wikis. Which of course doesn't directly translate to KaW, but I expect shortlists the number of elements to initially consider when trying to arrive at one's own particular approach to things.)

[e.g. Within that link is a reference to Troops Secrets Revisited (by Nicky Poo aka Russian Moster)  - which is helpful when trying to acquire an overall feel for the nature of the beastie.]

In the end, the answer, of course, depends upon whether you are attacking or defending.

Yet, unless you have duplicate gear (and *jewels*!) across the board, you have to pick one set of jewels or the other. It being too onerous (and expensive) to be frequently switching jewels back and forth.

For the moment, I guess, most defending will be done under shield. Hopefully the difference in additional damage for lack of Defense jewels nets out.

Additional / continuing thoughts about 'best' jewel/rune combinations welcome.

e.g. hHoo vs hdoo. (lower case - troop specific, upper case - troop generic = Enhanced Health, Enhanced Defense, Army Offense)