You should never bring anyone on the team unless you feel they are awesome and will add value. I believe the first 12 team members will dictate the success of the company.

That being said, you can bring in team members and give them equity that vest over 4 years, so that there is no risk to your company if they don't workout. So if you feel you need the accelerator to be successful, do what you go to do to make it work, without loosing control of the product, direction or major equity (as you'll need it for future rounds of funding).

So if you can negotiate the terms to be entrepreneurial friendly from the incubator, and get their money - then do what you need to to to be successful ... even if they aren't happy - you're the entrepreneur, not them - which concerns me a bit that they are mandating you get people on your team that you don't want/feel you need.

Hope that helps.

First and foremost, I believe that team and added value is everything for an early stage startup. Every founding member should be an indispensable asset to your business.

With regards to bringing in other experts as co-founders, ask yourself why this particular accelerator would make such a demand. Can you think of a reason why they would not reassured by your proposal to bring in these experts as hires rather than co-founders? Have you validated your initial approach with people other than angels (e.g. successful founders of hard-ware based startups)?

Lastly, ask yourself what your company has to gain by going forward with this particular accelerator. Do you feel they represent a unique opportunity that you could not find elsewhere? If so : see if there are ways to address their concerns in ways that that would be acceptable to you (e.g. appropriate vesting schemes that would protect your interests).

If design and logistics will be central to your business' long-term success, it will make an investor more comfortable to know that those key players have some skin in the game. But, finding a co-founder quickly just to satisfy investors doesn't mean you'll choose the right person, which is more important.

What about finding the employees you intend to hire after funding, and beginning to build a team now? If investment options are limited, work with the accelerator to craft a decision that satisfies you both. If you believe investors will be more abundant, pay to finish the design yourselves, launch on Kickstarter, and then weigh your options again later.