IMO, the suck. The possibility for a temporary boost in a team's skill isn't worth the possible downside of language, cultural, or financial issues that the team will likely face in the future.
As a fan, it sucks to see players who aren't very sought after in other regions take the spots that potential upcoming talent could have used on teams in other regions. This is especially egregious when said team is in a region with a large player base and massive potential.
I think it's more important for teams to invest in the upcoming players in the region. Even if it causes a temporary downgrade in performance. Despite being a risky investment time-wise, they should be better financially and more importantly, be better in the long run.
It would suck to have a region's best team be only 60% composed of players from that region.
However, I do agree with importing support staff. Coaches, analysts, and scouts from other regions are great pickups - their experience is their most useful trait. I emphasize the need for great player scouts. It's already been proven to be a good tactic - Immortals being the prime example. Rossy, Asuna, jcstani, and more.
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