I am a Gen X and not fond of ties and the thinking that goes with them. While ties can look very smart (think James Bond, ABC and Duran Duran) they can also look mighty silly (think Kmart shelf stocking boy).
I judge a person by who they are and what they can do for me. One of the most impressive business speakers I have ever seen was wearing a Space Invaders T-shirt and sneakers. He looked like a tech (and was) but when he opened his mouth…!!
I say encourage your staff to be true to themselves because trust comes from integrity not suits and ties. If a person is comfortable they must surely sell better.
If you want suited pros then hire that type of person. Just be sure they own a couple of $2,000 Hugo Boss suits they love and not something they bought for $199 to try to impress you.