Don't see similarities with Tata. Tata started with a bang, won his first Clasico, had a 6 point gap over Madrid after 14 games and then fell behind in February, spiraling downwards continiously. Lucho started with losses to Real Madrid and PSG, many narrow wins, struggling to score with many late goals, people asking for his head. But now in February Barca is clearly improving from that. Goals are flowing (if Suarez would finish individually it would be even clearer), defensive structure is stable for the most part, pressing is getting better and not worse like previous seasons, motivational and fitness levels look okay and Atletico are Barca's bitches. Clear upwards trends in February unlike previous season. Midfield control will never be the same without prime Xavi and that's it, get used to it.
Oh yeah, and I have to emphasize again how much the defense has improved, especially at set pieces. Last season every second or third goal came from set plays. Tata said he can't do anything about it unless the players start to magically grow. I already wrote back then that it's not only about height. Real Madrid under Mourinho were very bad at defending set plays, worse than Barca despite being a tall team. It's also about organization. A small player can block a tall one from connecting properly with the ball if he stays tight and impedes him correctly and doesn't lose his marker easily.
This season Barca have conceded 1 set piece goal in La Liga with more or less the same team and survived all set pieces against Atletico in 3 games with Pique-Mascherano.
If you pay attention there is also a lot of variaty in offensive set plays. Already scored 8 goals coming from set plays, as many as the entire last season. There are lots of studies moves.