by vardamir
These knowledge tiles (such as you already mentioned #13 and #14) show not only the bonuses when taking a specific action, but also the original effect of taking that action.For example, if you use your die to get workers (which normally you get 2 workers) these tiles show what you get when taking the action.
On #13 there shows 2 workers and 1 silverlings. These are not the bonus but the action's benefit for taking that action, which now not only just 2 workers but also in addition 1 silverlings.
On #14 there shows 4 workers. These are not the bonus but the action's benefit for taking that action, which now not only just 2 workers but 4 workers instead.
So when you have those 2 tiles, you get 4 workers and 1 Silverlings for taking a "get worker" action.
Hope this help.
Thanks.