A few things work in the network's favor in this situation (disclosure: I work at the Filecoin Foundation: I guess David and I are tag-teaming this). Firstly, the proofs that storage providers have to provide to the network are designed to work per replication. So you can't store just one copy, and claim you're multiple providers storing multiple copies.
Secondly: storage providers aren't anonymous, and in fact compete on additional features on top of the commodity storage offer. At the most basic level, you have orgs competing on geographical diversity -- so you have PikNik https://www.piknik.com/ or https://www.sealstorage.io/ in the US, dcent in the EU https://dcent.nl/ . And then there are other contractual requirements that let storage providers offer distinctive services, like the use of renewable energy.
Thirdly: the economic requirements of the Filecoin proofs at this point (constant availability, a reasonable amount of CPU/GPU power, an initial FIL stake that can be removed in the event that you fail to prove in a timely fashion you're storing the data), mean that the optimum storage provider setup is pretty professional -- you really need a presence and fast connection in an extremely reliable hosting center, a 100TB or more, and so on.
So, I'd say that there's a (potentially contingent -- i can imagine see the entry price for filecoin storage provision going down) entry barrier, and a lot of meta-data that can, and is, being used to make decision about which SP's to make deals with. So, for instance, Estuary and I believe the other front-ends use historical and business data to determine who they're making deals with.