consider this.

factors multiple recruiters multiple recruiters
speed
With many recruiters working on the same role, you will get a quicker turnaround as the recruiters compete to be the first to present candidate profiles.
Finding talent that is a “best fit” for the client requires a detailed sourcing and matching methodology. The best recruiters take pride in understanding the clients’ hiring needs and candidates’ motivations in order to make the perfect match.
quality
Because of the time pressure to present candidates faster than the competition, the quality of the talent is usually compromised for speed. Candidates might not be adequately screened, briefed or qualified to ensure they are the best fit for the role.
Clients will be given priority access to the best talent in their industry. The recruiter is able to provide a shortlist of the best candidates from a wide variety of channels (both active and passive).
employer brand
Different recruiters will represent your brand differently – sometimes to the same candidate. This could be confusing for the candidate, and might harm your employer brand in the long run.
The recruiter is your first point of contact to your potential talent. Working with one recruiter exclusively will ensure consistency and clarity in the way your employer brand is represented and promoted to them.
candidate experience
When a candidate is approached by multiple recruiters for the same role, their experience with the brand becomes diluted and fragmented. Candidates’ expectations may also not be managed properly due to the need to deliver against time and competition.
The recruiter will have more time to brief the potential candidates thoroughly and keep them engaged – reducing the likelihood of them withdrawing from the recruitment process.
recruitment efficiencies
There is no incentive for the recruitment firm to offer a discount or be fully committed, especially more so if they have other clients who are working with them on an exclusive basis.
Clients can negotiate for a discount in return for a stipulated period of exclusivity.