Why not? Because Lansbury is nothing more than an enthusiastic, potentially useful tyro whose qualities are quite untested. Rather ask why.
But either way, I'm talking priorities and you're talking absolutes - not to mention the disingenousness of talking about the two brightest talents to emerge from the last six years as "two 18 year olds".
If Diaby's nothing more than excess fat, we've got so much of that we're in need of lap-banding not a diet.