That's exactly how mine, and other guys' I ride with, are made. After you cut the arm in half you grind the cut ends down to almost a point to allow for the weld to fill in, put a piece of solid bar between the ends and weld it up, then you lay strips of plate down the outside of the arms and weld it all up. You need a jig to keep everything lined up, of course. And dont even try it with a low amp mig, unless you know something I dont. (Which is EXTREMELY possible!!)
Seen 'em take some tough licks and hold up. If welded good, you'll waylay a rim before you hurt the arms, or the dropped spindles we made.
Maybe just been lucky so far!
Larry