Morale wise it's probably better to do it in one large chunk instead of smaller servings where people are wondering if they are going to get cut in the next round.
But how would you know the one large chunk will be the only one? Layoffs are bad for morale regardless of how it is handled. I've been through both sides of a layoff and it wasn't fun either way.
> But how would you know the one large chunk will be the only one?
You can at a minimum guess from the size. Take for example this cut - roughly cutting 600 from 6-7000 means cutting 10%. Unless Blizzard is seriously inefficient, another such cut of 10+% would start doing major damage to operations. Hence, you know there probably won't be such a cut.