I really don't see anything wrong with shooting any deer that your proud off, with the only exception of shooting yearling deer. Leave them alone at least for 1 yr. In the province I hunt we have doe tags to help manage the herd. Most people that get drawn for the doe tag usually shoot the first decent doe they see and they are done for the season.
Our deer population is not high like in some places but we do have a good size herd for the size of our province. It is growing rapidly in the past few seasons. approx 3-4 yrs ago it was below 60,000 now it has climbed to over 100,000 animals approximately.
If you want to shoot a smaller buck go ahead as long as it is kone legally. I personally will pass on a immature buck unless the season is getting late. specailly if I have a doe tag to fall back on for meat.