This is the original GA. Totally different to what we have now. I think this would have been the original concept before there was a tweak to the matching formula. I guess the OP had kept their whole roster slim and then there was a change that only took into account a certain percentage of your roster.
Something like that anyway.
By concentrated GP they mean min-maxed to the gills. They 'suffered' in that they didn't have many teams for TW and little GP to deploy in TB. However, in GA they probably went 12-0 every season. Fun stuff!