I never heard what people said about this being an arrangement of the main FE theme. While the style is similar I don't think you could qualify this as an arrangement like that. Regardless, this is still one of the best tracks to come out of this game. It feels like I'm saying something like that about every song, but I really love this game.
This is an arrangement project of the game Fire Emblem ~ Gaiden, released in Japan for the Famicom Disk System in 1992. The original tracks are made using the hardware limitations of the original device, limiting the compositions to chiptune sounds. Thus, I made it my mission to upgrade the sound and arrangement of the tracks to what I call the "enhanced GBA standard". This is made using the instruments found in the Game Boy Advance iterations of the same franchise, without restricting myself to any hardware limitations. This results in a rich sound which still hopefully sounds nostalgic to people like myself who grew up playing these games on the GBA.
Do you want to use this cover in your own projects? Feel free to do so without restrictions. However, I'd find it very interesting to see your finished work, so please message me about it!