Why would Germany hurt his triple central alliance?
OK, I guess taking Mar would not be a good idea strategically. I'm doing my commentary off-the-cuff without looking at the history of the game or the diplomacy underlying everything, so I tend to mention short-term tactical things.
The players have an inside view and can judge the diplomatic situation far better than I. But when you're heavily invested in a game, you often overlook the objective analysis of the raw position on the board. Hopefully I provide a viewpoint that helps you evaluate the game dispassionately.
Please do not ever think that what I recommend is the best move. Sometimes a move that is strong tactically is inferior when considering the diplomatic relationships between the players.