*Special thanks to Elcyion and his allies from K28 for contributing their game guide to us!

Here is much information in this table, please open the picture and zoom in to read. 

How to make efficient use of your friendship gifts? The commanders are sorted(top-bottom) based on Leadership & Combat rate. The gifts (only) give 2x bonus exp to the set of commanders below

Friendship Levels

Stars = Stats gained/level - Levels increased by 10exp/Level (5 starts = +5 of the same stat per level up)

Example - Seg at LvL 5 is 43 CR and 36 L. If you level him further he will be at 48 CR and 40 L.

The hypothesis is that commanders with Star L5 and L4 should keep a distance of 2-5 exp LvLs at most. Because the increase of Exp/LvL is just not worth focusing on 1 commander. Until the current data changes on Commanders at higher levels.

Commanders with Star L5 should keep a gap of 5-10 LvLs with those with L3, an L2 should be approximately 8-20 levels behind an L5. Current thinking is that u need at least above 1500combat rate as a t4 player if there is a big gap between players' combat rate it won't matter how many more troops you get from leadership. But as with most things its mostly a bit of balance even with a total focus on Combat rate you will pick up leadership here and there. Everything looks easy on paper but as we know in RL nothing is really easy and this new friend stuff is highly Complicated when you get into it.

Bonus overview increase

Leadership Every 100 points 3k solo and 10k rally army size increase

Combat Rate every 100 points 2.5% total attack Def Hp

Command every 100 points 20 units every 4 hours

Aptitude every 100 points 20min every 4 hours

Finance every 100 points 10k gold per 4 hours

*Tips:

Food is scarce so it is better to not waste it on a bad commander but to save it up. Use the saved up food when you unlock a good commander which has the stats you need.

Some people are currently focusing the aptitude route this is just a warning that your troops even with higher technology will perform a lot worse and be made of paper. Only go this route if your never going to attack or be attacked. You cannot redistribute gifts given currently and the mats are in short supply even for big spenders.

Conclusion

Looking at the bonus each individual stat gives, focussing on Leadership (Army size + Rally size increase) and Combat (Total Attack, Health and Defence) is the most beneficial for solo players and rally leaders. Currently, Combat has a higher value and benefit than leadership at least up to 1500-1800 combat rate. Most of the commanders have both Leadership and Combat stats, so focusing on leveling those commanders up would be the way to go. The Command stat would be beneficial for T4 players, for T3 players this stat is not great. Make sure you use the right gifts for each set of commanders to receive the 2x bonus exp. Unlocking BD commanders with the Leadership/Combat rate stat, will boost your bonuses. Rally Leaders have to keep buying those gift packs every time they pop up missing 1 or 2 of those and your viability in a highly competitive kingdom can seal your doom.