I've played it as the retinue can only take rhinos and not landraiders as the "normal" transport option provides. And if the infantry is the main goal then I think that is quite alright.
But as the armoured company goes… well as it is now, the most like an armoured company you can take is a retinue sitting in landraiders (4 of them) and then give them 3 predators, but for this you will be charged a whooping 750 points… Not really something that I think it’s worth. And you’ll get a whole lot of blast markers when your landraiders go down and take the transported units with them.
So sure, if only 1 support is given for each retinue, I can’t really see the problem of not having one of the options be an armoured company. You’ll still only get one and you’ll have to choose between a whole lot of other nice stuff.
And I still have problem seeing the use of havocs
They have in the list noting to make them worth taking, everything they can take, the normal retinue can as well, and then some.