I love playing the dutch against the london! in fact I just wrote a small blog post on it: https://www.chess.com/blog/CNoahSay/the-classical-dutch-white-avoids-fianchettoing-the-london-system
But that is not the London. Just putting a bishop on f4 does not make it a london system, once white has played c4 it is pure dutch
Ok yes to play the london system white should be playing c3. Though the strategy that Simon Williams recommends in The Killer Dutch is still what I point out in the blog post. Basically aim for a quick e5. It is simple enough
Here is the game that he gives to illustrate the strategy:
I love playing the dutch against the london! in fact I just wrote a small blog post on it: https://www.chess.com/blog/CNoahSay/the-classical-dutch-white-avoids-fianchettoing-the-london-system
But that is not the London. Just putting a bishop on f4 does not make it a london system, once white has played c4 it is pure dutch