Maybe. I wouldn't actually swap him for just Cavani and Silva having thought about it. I suppose the point I was trying to make was that I don't think he'll be good enough to make up for Barca's deficiencies in other areas.
I don't think it's that outlandish to suggest swapping him for the world's best defender, one of the best midfielders, and one of the best strikers in the world(maybe Cavani was a bad example, let's say Suarez instead) could benefit the team, it's unlikely all three would get injured at the same time for a start.
Barca have only won 4 out of 9 league games since Messi returned from injury, and have lost 3 out of their last 6 having previously only lost one league game all season. I'm not blaming Messi for these results, I just think that with a better defence and cover for an ageing Xavi they could have done better in that time; with or without Messi. I don't think Barca would miss Messi as much as poeple think, in fact I'm pretty sure they've scored a similar amount of goals with or without him in the team this season, though admittedly he missed some cup games against minnows and has played in most of their toughest games.
Best player in the world, but, as long as they strengthen in other areas, I still think Barca could cope without him. They won a Champions League without him, and that was with an inferior, though more exciting, team to the one they've got now.
It doesn't make much sense, but, I rate him as the best player in the world, in the top three of all time, and still feel he's a tad overrated.