So are you asking if the scanners can be connected to one machine (the file server), but operated remotely from client machines? (is that what 2 different locations means?)
Remote use of scanners isn't really supported in XP (they can't be shared) - though you could do it using remote desktop (and I think some provide software to allow 'sharing'). But of course the nature of a scanner means it needs something to scan - so somebody has to load the to be scanned document (ie, not easy remotely, unless remote machines are in fact near the file server). Can't see any problem using 2 scanners at once other than usual drain on resources - scanners can be quite heavy that way.
Why not connect the scanners to separate machines - they can still be shared as effectively (or not) as connected to file server, and you can have them in 2 different locations.