Neither of those articles use the same methodology of minutes per assist though. No one is claiming Nani has the most cumulative assists or even assists per game. Per game is a pretty awful state btw. Only used when people are too lazy to work out how many minutes someone has played and how regularly they achieve something every 90 minutes.
That kinda goes away from why I think its a useless stat, even if we took each game to be 90 mins for a player (which is too high), the first article had Beckham creating an assist every 157 minutes I think - obviously it'll be lower as he wasn't playing 90 mins each time he stepped on the field.
The second article saw Beckhams no of assists drop from 152 to 80, nearly halved FFS, thats not a slight anomaly in counting, its a completely different method. This seconds article gives Cantona's mins per assist as 250 if we take each game to be 90 minutes - now we know Cantona spent as much time kicking the opposition/fans to last a full 90 mins each week, so you'd expect the the real figure to again be significantly lower.
The Opta method has Cantona having 246 mins per assist, on the face of it not far from the one above, but if they've used the same amount of total assists, then you'd have to infer Cantona played nearly 90 mins each match, which above proves he didnt (I know we didn't sub him off very often, but it still happened), so can only conclude Opta have a different way of calculating assists compared to the other two.... Note Beckham and Henry fall from 1st/3rd to no where near across the articles.
Now I'm very much a stats and figure kinda guy, but I must admit I keep forgetting to follow the Opta account on twitter, all it does is sprew out really irrelevant figures that make me wonder how someone gets paid for this stuff, and this one to me proves it - they've tweeted a completely arbitrary stat that can basically be calculated on whatever criteria the statistician deems fit. I think we can all agree Beckham was fantastic getting the ball into the box from wide, few can hold a candle to Fabregas at creating from the edge of the area, Henry was a freak of nature, and Reyes really doesn't sit with this company.
As a bit of stats geekery to finish, none of these mention Scholes, using the first link (and i think the arsenal blog mentions it), his assist/game ratio is very poor, yet theres been a picture going round twitter comparing Scholes/Xavi/Pirlo, and in around the same no of league games Scholes has scored and assisted twice as much as the other two.... 3 of the most creative midfielders of the last 20 years (throw in Zidane/Iniesta in that mix, and Gerard too, who the first link puts as one of the highest creators in Prem history)