Using Et Al in a Purchase Sale Agreement

[Jesse Brown]

I am in the process of signing a wholesale deal for a single family house owned by three siblings that live in three different states (Washington, Oregon, and California). None of them are tech saving so docusign, scanning, and emailing are not really an option. Here is my specific question - if I have the primary owner (sibling taking responsibility for selling) sign the PSA with et al will that be a valid/binding contact for all owners? Will a title company accept the contact and track down the owners for signature for closing? I appreciate your help!!