They won't make me believe it's hard to find japanese talents in a country over a hundred million souls.
This isn't a problem inherent to Japan, but to the whole video game industry. There is a reason average ages in most studios don't go over 30, that people have garbage wages and are paid "in passion", don't count their hours because they don't have families to feed, are fresh and naive out of uni and are doing their dream job of development. The only people that oversaturate the market are found in creative jobs because they don't have much choices outside of games (especially game designers and testers). Programmers and engineers tend to get out once they start having families of their own and need actual money and stable careers to back it up which they can find in most firms that aren't about video gaming.