depends where they were, ginge. sometimes you don't have to be touting a rifle out in the sticks to be in danger. most of the boys and girls who suffer mh issues post deployment in our unit aren't out on the area, but still within danger of mortars etc. in fact the only injuries we've had have been to guys in camp.
and having spent some time in the falkands
you can probably suffer from ptsd etc as a result of extreme boredom. 
tbh, the relationship issues will be much the same - the spouse at home will have been a single parent for 4/6 mos, and will be in a routine. the deployed partner will have been in a totally different routine (whether that involved actual combat or not), so from that aspect it's not much different. his prior experience will still benefit the less experienced lads and lasses from that pov.
and it is really important that the experienced sncos take this stuff seriously. really important. because if they have a junior colleague who is having problems with his wife/ starting to lose concentration/ having difficulty reintegrating further down the line, it is imperative that he knows his superior is going to take him seriously and know the route to take for support. and not come out with the age old 'nah, mate, no worries here, been there, done that, pull up a sandbag, let me tell you all about the time we got bombed in kabul, i'm well hard, me. blew me leg off and i've never had a problem. ptsd's for pussies. what d'ya mean yer missis isn't talking to ya. give her a good seeing to and she'll come round' bollocks that's been way too prevalent for so many years.
not suggesting that's how your husband is at all
but (even if he doesn't need the briefing himself) he needs to be there to show his support for his subordinates, and to his superiors. they need to know that they can trust him to do the right thing by his boys and girls too.
it might seem a bit over the top in this particular case (don't know where they've been) but it sends the message to everyone that their welfare is being taken care of. after every op tour, not just if they were injured/ under fire.