Lords, we've put together a table of the Alchemical Laboratory's bonuses. Now, you will know what bonuses you should upgrade first.

Note: initially, the upgrade cost for all troop types is the same (spearmen, cavalry, ranged troops, knights, siege units, and scouts). After you have upgraded one of the troop types, the upgrade cost is increased to a new level for other troop types. 

For example, let's say you have upgraded your knights. Now, the upgrade cost for all the other troop types rises to level two. If you then upgrade your cavalry, the cost for all the non-upgraded troop types will rise to level three, and so on. 

What troops do you upgrade in the Alchemical Laboratory?