I think it is really odd that he buys a cartographer, then decides to stack back on top... EVERY time. I'm not really sure what the deal with that is, since he could've just played it, looked ahead and such. Although I do like the idea of grabbing a cartographer, Grand market not so much, the extra $2 and + buy seems frivolous with 10 herbalists in the deck.
I don't think buying that many herbalists was a bad idea. It seems much safer to do something like buying 10 herbalists in a bloated deck vs. a ghost shipping engine, then trying to sneak in a few estates at turn 13 before a single province was bought.