Does anyone have some tips?
I couldn't find any way to counter the kodachi and by own raiding, forces would always get destroyed. My enemy's economy felt like it was 4x mines (he was using a sizable tank ball with 6ish ravens as well with a good amount of porc).

He was smurf?

Yeah, your start was definitely too slow. Having a few more daggers before the second constructor comes online would let you handle his initial kodachi more easily. The switch to scalpels was much too fast as well. Daggers and bolas handle kodachi better. Tanks can't build many units early so they have a really fragile start. If your daggers are probing his expansions on multiple parts of the map, he won't be able to defend them all effectively. So just keep building daggers/bolas until ogres start appearing. That's when you can bring out scalpels (or vs stardust).

You also excessed a lot of metal due to not having caretakers fast enough and your factory running out of queued units. 40% of the way through the game you had lost over 2k metal, so that's part of why you felt like he had a lot more metal than you. You should probably be using repeat queue for now, and just change the build order when you need to react to a switch from your opponent. Stay away from manual re-queue until much later.

Also, at some point you should have started reclaiming metal from wreckages and the starting metal that is available on that map. Once you have the metal excessing problem solved.