Thinking about it I'm wondering if they have some what limited them selves by wanting 4 birds into 1 C-17. With the size of most of the birds you would likely need a second aircraft just to transport the mission personal. Not necesarily a bad thing but if there is an issue with one of the transports then its a 100% loss in mission capability compared to say if they split the mission crew and birds equally (ie: 2 helicopter + associated crew's per each transport) would mean only a 50% loss in capability. Not saying 50% isn't a big hit but leaves some options rather then no options. Also allows you to go for a slightly more capable helicopter as well more easily able to load/unload when you don't have everything packed in so tight that one slip up could stuff everything up. Food for thought?
In regards to the Venom, I honestly don't see that being a contender at all based on the current wording of the program, 4 birds to 1 C-17, The size of the Venom would only allow you to fit just 1 in there maybe 2 with work. With the wing box section in the hold the Venom in about half a meter too tall so at the very minimum blades will have to be removed, That aside they are also fairly long so the tail boom on one would also have to be removed. Not knowing anything about them I have no idea how much work would and time would be required in removing and fitting them, Is it straight forward, Is specialized equipment required,?? For what they want it for the Venom in any case appears to be a bit of overkill.