I just started a side cleaning service (which has the manpower to cover larger commercial needs) with my business partner and I'm interested to learn about different resources, especially if there are popular platforms, that property managers or real estate professional use to help find services to maintain their properties.

I have the tools, time, manpower, and ability to do the job, just need the backers to do it..

It will cost you, but they also have the man-power to get it delivered, set up, and styled well. 

Although searching through long lists on MLS and/or consulting with a realtor might get you one or two properties over the course of a year, it's very unlikely that you will have the time/man power to make an effective use of this method.

Be sure your contractor can dedicate themselves to your flip full -ime and has the manpower and expertise to do it.

If you are considering hiring two general contractors to get the job done in half the time, you are trying to do their job of coordinating multiple work fronts, manpower, equipment rentals, material deliveries and sub trades and you are expecting to do it better.If you were to do this, you would in fact be the general contractor and be paying the profit and overhead of 2 other general contractors while spending your time doing their job of managing the work.

We have the manpower,the construction know how.

If they've got the manpower and machinery to tackle the job quickly, I'd definitely say it's worth the cost. 

Project takes longer than expected due to any number of reasons (permit delays, weather delays, parts and supply delays, man power delays) and that increases your carrying costs.

They do not have the manpower to be chasing every investor crossing the grey line.