I think fleece is putting it nicely. Lawrie's ceiling, if he could stay healthy, might not be at Donaldson's level anymore and his health is a big if. And I don't know why people are really hyping Barreto that much, yes he has potential, but he's only 18. In two years time he could be a flop, but once again, his chances of being an MVP calibre player are very very slim.
We got the best 3B in the game for a constantly injured 3B, a high potential but very young prospect, and essentially two filler arms. Trades like this don't just happen all the time