We are a LLC based in DE, owned by two non-resident aliens.

You must treat three kinds of foreign source income as effectively connected with a trade or business in the United States if:

You have an office or other fixed place of business in the United States to which the income can be attributed,

That office or place of business is a material factor in producing the income,

and The income is produced in the ordinary course of the trade or business carried on through that office or other fixed place of business.

As long as the consultant is located in the US, it would not matter if employee or independent contractor. He is carrying on your business in producing income.

https://www.irs.gov/pub/irs-pdf/p519.pdf

If you use the services of a payroll company, the worker will be your employee.

You may be thinking of using the services of a LEASING company.

As I mentioned,

You must treat three kinds of foreign source income as effectively connected with a trade or business in the United States if:

You have an office or other fixed place of business in the United States to which the income can be attributed,

That office or place of business is a material factor in producing the income,

and The income is produced in the ordinary course of the trade or business carried on through that office or other fixed place of business.

As long as the consultant is located in the US, it would not matter if employee or independent contractor. He is carrying on your business in producing income.

https://www.irs.gov/pub/irs-pdf/p519.pdf