I remember those games!
I also had Valis III and Target Earth. Not being particularly good at shooters, I found Target Earth to be pretty difficult.
I borrowed Warsong from a friend of mine and beat his copy without buying one of my own. A couple of years later I bought Langrisser for the PC Engine.
The anime Samurai 7 reminded me a lot of M.U.S.H.A.
Of the games I mentioned, I only still own Langrisser. If I remember correctly, I traded all the old Genesis games I had, with the exception of Lunar and Lunar 2, for my original Playstation.
The biggest disappointing thing about most of the early Japanese games released in the States, was the changes in the box art.