Although we agree that using statistics is not always the best method I have to disagree with your analysis of Modric. I do agree he was not at his best for this particular game, but you have said yourself that one game doesn't make a player bad. So if we go back to my previous statement ...
So I would suggest we look at what each player offers the team, compared with his weaknesses and then judge if the gap is too wide and the weaknesses are in excess of their strengths.
... I would have to argue that Modric must offer more to a side than his relatively low direct assists and goals. (which are just statistics by the way so be warned not to over use them). I think Modric is not only a tenacious midfielder that can keep hold of the ball and pass well, rarely giving the ball away (Milan game excepted). He is also one of the key players that can produce a cross field pin point a pass to Lennon or Bale, who then break and then cross the ball to become the players who get the assist for the goal that is scored. Modric then gets not direct statistic against his name, but truth be told, the goal was down to him.
These are only my opinions of course but if you don't believe me, or can not see how good Modric is then maybe a quote or two will strengthen my position, from the main man himself.
"I think he could play for anyone, he's that good. He's a fantastic footballer, amazing player, great brain," he said. "Not only is he a great footballer, he's strong, he works for the team, takes knocks and gets on with it." (March 2009)
"Alex Ferguson said to me after the game last week that he thought Modric was fantastic," (March 2009)
" Luka's key to everything that's happening at this place...if you want to move on to higher levels you don't start flogging off your best players - to anyone." (May 2010)
“He (Modric) is such a fantastic player if we start selling such a player like that then we might as well all go home” (Dec 2010)
'I wouldn't want to sell Luka Modric for £100 million,' he said. 'He's such a fantastic player. If we want to build a team to compete in the Champions League every year, we can't be selling Luka Modric.' (Feb 2011)
Now he has been saying these things for the last 2 years, so they are not designed to inflate his selling price and whose judgement is more accurate, experienced and worthy of being accepted? HR or GK? (not a personal dig Gk but just saying that none of us can come close to his opinion. We can give our own and we do not have to agree with HR but we had better have something really worthwhile and meaningful to say when we do.