One issue is with La Liga and the style of the league, I don't think its any worse than the EPL at all at the moment, but its a different style, Italian league is much slower, top to bottom, EPL loves its 4-5-1 at the moment with bottom teams over the past 7-8 years often parking the bus, though more recently you've got a few teams that go all out banana's trying to win games, those guys are at the bottom while teams that more often park the bus are doing far better than they ever used to. Stoke, Sunderland(sometimes), Bolton, Blackburn but even most of those are more offensive than they used to be.
La Liga though, its just about balls out football at times, teams rightly have a go at Barca now and then, and often after goign 1-0 down they will attack more, La Liga in general don't seem to care about goal difference and the end of the season, but about attacking footie.
Barca/Real beat teams 7-0 far more regularly than EPL teams do, as such the worst players in the team have much improved stats vs the worst in the EPL. Arsenal go away to stoke and scrape a 1-0, Barca go away to Levante and have trouble keeping it in the single digits.
Alves's crossing is, wild would be a fair word, he puts it behind the goal or out for a throw more often than getting it in the box, he takes a lot of freekicks and Barca are very good at reacting and getting the tap ins. Alves also does what Ronaldo does a lot, shoots frequently, with power, but often drops for other players to tap in. He's quite horrible defensively, is one of the worst divers/cheats in world football and isn't nearly as good as people think offensively.
If he played the same role at Chelsea he'd have 1/4 of the assists.