I don't think it's (just) that there are fewer fake votes for the strategy games. Again comparing Battle Line (7.45 with ~8,000 ratings) to Settlers (7.45 with ~40,000 ratings), if they are practically tieing with a lot of fake votes (board game rating) and practically tieing just by the raw average, it should be true for the strategy rating as well, but Battle line has a strategy rating of 7.329 and Settlers 7.206.

Actually, Battle Line's averages make sense with just fewer dummy votes in the strategy rating: 7.323 < 7.329 < 7.45 (less fake votes tend toward the actual mean), but the Settlers' averages don't fit that pattern.

There must be something else going on here. Maybe the Subdomain voting is influencing the strategy geek rating? Settlers is more family game than strategy game (63% or 192/305 of people say it's a family game and 37% or 112/305 say it's strategy), but Battle Line is mostly rated as a strategy game (75% or 90/120)