* "Laddies" is a somewhat archaic and informal term. It might be better to use "boys" or "young men" depending on the context.
* "Pretty" can be a bit ambiguous when describing males. Consider using "handsome" or "attractive" instead.
* The sentence lacks flow and could be more descriptive. For example, instead of "dropped by," you could say "visited" or "came to the office."
Here are some alternative versions of the sentence:
* Three handsome young men visited the office.
* Three attractive boys stopped by the office.
* Three young men came to the office to see us.
Ultimately, the best way to phrase the sentence depends on the specific context and the desired tone.