Every single person has things that they are really good at and others that they're (shall we say) not so good at. We cant all be good at everything, so the best solution as an employer is to empower staff in their areas of strength and move the weaker areas elsewhere.
There is very little chance that your staff are all good at the same thing as much as they won't be weaker in the same areas. This is a great thing as you now have people who are great in different areas. This could mean your entire jigsaw puzzle, that is your business, can be complete and become that streamlined well oiled machine you've been aiming for. If only it was that simple!
Just because someone is strong in the skill of marketing, doesn't mean they want to sit and do marketing all day. One of my employees once was awesome at organizing, but really hated doing it so I couldn't use this untapped skill to my advantage without creating a disgruntled employee.
So here is one solution that I can share with you. It helped the business, made the staff member feel like they really contributed to the growth of the business and used the skill of the employee, even though they didn't want to perform the duties.
As I recognized the strength in each of my employees I sat them down and asked if they would like to perform that role within the business. It was easy for the ones that were excited to use their strength all day long, but for the others I came up with another plan. I asked them to create a full document, a manual, on that area of expertise and apply it specifically to my business. The idea was met with open arms and I didn't have a single person turn me down.
So what did I end up with over time? Well I ended up with an employee that felt they had (and they really had) contributed to the company moving forward and succeeding. I ended up being able to share that knowledge with other staff members and any administration help that came into my office. And I ended up with a fully documented office with a manual for each position and skill required to run that company. This was then used to address weaknesses and work on the personal development of the staff members creating a well rounded and awesome group of people willing to sit on my team and help drive the business forward.
So don't just ignore weaknesses, work on them with people. And certainly don't dismiss the strengths of your team, capture that strength and build the type of employee that has your back as much as you have theirs.