A lot of people forget that IT departments in medium to large companies need to be able to remotely manage equipment, Macs are "annoying" and iPads are damn near un-manage-able.
So while a lot of middle managers outside of IT think that iPads are "cool" and push for them, they get a lot of push back from IT due to their impracticality and the amount of time/resources it would take to manage.
A Surface Pro has none of these issues. It is a standard Windows 10 PC which can be managed via System Center/AD/GPO/etc, so they're non-effort machines for enterprise/IT.
So that, I suspect, is why you're seeing so many so quickly. Internally non-IT management wants a "tablet" and the IT department is deflecting from iPads onto Surface Pros because it is in their best interests to do so.