I just recently started playing with my Japanese. I thought that almost three years into my Enlisted life and having only logged 13 games with the Japanese, it was time. 
So, after getting my first MG’s squad quickly learned what I learned about the Allies and Russian level 2 MG’s…They sucked. So, I figured I would try out some of the BP machine guns and found that the Hotchkiss 1922 was a fairly good level two MG, once you get past the gay looking loading mechanism that is. 
I ended up buying all four and like them much better then the tech tree MG’s.
So now, all my level two factions with the exception of the Germans use BP MG’s. I use the Allies Chatellerault M24/29. To be honest, I’m not sure it’s better then the Bren, but sounds meaner. 
It’s drawback is the gay shark fin mag sticking out the top like the rest of the Allies level 2 MG’s. 
This is why I am preaching the need for DF to make at least one of the BAR’s level two, as at least the Americans had sense enough to put the mag on the bottom of the weapon where it belongs . The Russian RPK 1943 seems to be a step up on the Madsen. I actually love the RPK MG, the only problem is it only has a 15 round mag, which is not ideal in a heated gun fight.
The ONLY level two MG that I like in the tech tree is the MG13.