Powercreep in splinterlands, conformed!

Introduction:
The hypotheses is that there is a powercreep in splinterlands.
To prove this we need a way to quantify the monster power.
This was a work in progress:

• part 1 (melee)
• part 2 (ranged)
• part 3 (magic)
• part 4 (shield)
• part 5 (void)
• part 6 (flying)

The rules to calculate monster power so far:
Basic stats:

• 1 health is 1 monster power.
• 1 armor is 2 monster power any additional armor is worth 0.5 monster power.
• 1 Speed is 0.5 monster power.
• 1 attack is 0 monster power,
• 2 attack is 2 monster power,
• 3 attack is 3.5 monster power any additional attack is worth 0.5 monster power.
• Rare monsters are worth 0.5 and Epic monsters 1 more monster power.
• Neutral monsters adds 1 monster power for flexability.
• Ranged monsters are worth 2 additional monster power.
• Ranged monsters are worth 4 additional monster power.
• 1 mana cost is roughly 1.4 monster power

Ability:

• Shield, 4 - 0.5 * mana cost, free from 8 mana.
• Void, 4 - 0.5 * mana cost, free from 8 mana.
• flying, free from all monsters.

Result
Chaos legion cards are on average more powerfull than non-chaos legion cards!

This is the powercurve of the relative strength of cards, where left are the amount of low powered monsters (-2 monster power) and right are the amount of high powered monsters (+monster power).
The power levels are relative to the average of the whole set, the amount of monsters (bar height) is relative to fit the smaller CL-set in the same graph)
From this graph It becomes clear that the chaos legion cards are not overpowered, there are some non-chaos legion cards as strong. But splinterlands balanced the cards a bit better to have less weak cards. So some cards got a stronger brother since they were underpowered like:

Cards to mention:
Elemental phoenix is so strong it skewed the whole curve and removed from the graph:

On level 2 it gets explosive, that's wild, but i never seen him in action. anybody has experience with this monster ?

Final thoughts:
This is done on only a small selection monster with “simple” abilities for only lvl 1 monsters, but I think this shows clearly that there are less underpowered cards.
Any ideas for follow-up analysis?