As your number of staff increases, you'll find that you need to be more explicit. Real world people are complex creatures, and managing them isn't simple. What defines 'being a dipshit', for example? For some, it's being a pedant. For others, it's being slow to learn. Others think it's about obnoxiousness. Besides, rules like "fraudulent timesheets are a fireable offense" make it explicitly clear that 'we check these things', and avoid the 'but I didn't know it was wrong' excuses that you will hear with enough employees, commonsense be damned.

True but such is life. You make up for it by always giving people a chance first. You never fire on the first sign of dipshittiness.