I sure, you've seen three the most important war knowledge:
- Shaman's Influence on Enemy Troop Offense
- Shaman's Influence on Enemy Troop Defense
- Shaman's Influence on Enemy Troop Health
This three knowledge with the max upgrade will give you 20% each. You needed 23 oracle and a lot rss for this. Don't forget for using this bonuses shaman should be in the march.
Per Viking Helper it cost 33.56 B in each resource and 91.96 B in silver, less whatever knowledge cost decreases you may have. This from starting at the beginning of shaman knowledge.
These 3 knowledge types in the invader tree starting after completing Invader lv6, it would cost 38.85 B in each rss and 69.85 in silver and you would max out at 50%. You would also need oracle lv 31.
If you want only 28% in these 3 knowledge types it would only cost you 5.6 B in each rss and 8.68 B in silver in the invader tree and you would need a lv 29 oracle.
So if you want these knowledge types research them first in the Invader tree before the shaman tree.
