Thanks for playing. I am not an artist so I lean heavily on simple art and try not to get too hung up on it. I can only focus on so much as a solo dev.
You are absolutely right the wild card is more relevant than the theme and that is 110% intentional. 1) Two of the wild cards were suggestions I had the won the vote so I wanted to heavily use them. With this I find GWJ wild cards typically more interesting than just the theme as it requires working around more constraints. 2) I didn't want to make just another game set on a train like I knew most entries would be. 3) Using the word "teach" of "train" was intentional as well. I original had the type saying "train" but it didn't flow as nicely and felt very forced. I decided on more natural language. The original concept was more focused on a book/training guide but after I did the art and they looked like chalk drawings I figured I would lean more heavily on that concept and go with a chalkboard/classroom style theme.