Sales Engineers are the field services team aren't they? The terms are interchangeable (imo).
I am generally wary of companies that start cutting these types of positions. Field services teams at growing/thriving companies (at least in my experience) are forever short-staffed. i.e. as new customers come on board, existing resources become stretched thin.
To combat this, various schemes are employed in the short term, but if a company is actually healthy (i.e. growiing/thriving) they generally will hire on more field support people to accommodate the growth.... field services are the life-blood of growing companies.
imo, when you start cutting costs in areas of importance for growth (like field services), then you are structuring yourself for an impending buyout.
They shouldn't have fired those who help the Customers to fix issues with poorly written software on site.
Just look at any VMS software, new releases list pages of solved issues. Sometimes these issues must be addressed on site prompt. I think that a company which is getting rid of field support engineers, does not take responsibility for the problems with their system any more.