I would tend to look at it in as simple terms as possible: if you don't intend on accepting
Dechert's VS as it clashes with another option you'd prefer, there's almost nothing to be gained by interviewing and that space could go to another candidate, maybe one whose top firm is
Dechert.
In terms of spreading yourself too thin, it's hard to comment: I don't know your work rate/ how much you have to do etc etc. What I would say is that, while it's important to remember your health etc and not absolutely burst yourself, a life in commercial law will be one where you often feel spread a bit thin due to work volume and the sort of environment you're in. Personally, I don't think this should be a deciding factor.