Sure, but the problem is those guys aren't exactly cans. They're talented fighters that could easily win those fights, and in the process destroy most of the remaining marketability of a guy like Costa or Strickland.It comes down to money. The UFC is trying to cut corners by keeping costs down, all at the expense of the quality of the product. By using cans as cannon fodder, they've created a main event (Strickland vs Magomedov) and a premium slot on a ppv (Costa vs Ikram). If they did Costa-Strickland, it could be a Fight Night main event, but what's left (Magomedov vs Ikram) would be a prelims fight.
Follow the money.