He's not the same threat because he's not getting the same opportunities. Blatt and Cleveland like to use him as a three point shooter, but that's more about floor spacing than it is about Love's effectiveness as a post player. Per Synergy, as of January 30, Love was leading the NBA in points per post-up possession among players with 4 or more attempts per game. I don't know where that number has gone since then, as Synergy's numbers are subscription only, but I feel pretty safe in concluding that Love on Turner is not a matchup the Celtics should be trying to create. It's a moot point anyway, as Bass isn't likely going to defend LeBron for any significant duration.
Edit: NBA.com has post-up efficiency stats. Love is tied for second in the NBA among players with 200+ post up possessions:
http://stats.nba.com/playtype/#!/post-up/?dir=1&sort=PPP&CF=Poss*GE*200