From: The Great White North!
It is always good to remember that there are three different ways of setting this sort of action up:
1: Cargo: This method is great at replicating the loading/unloading process, stressing capacity issues and making players decide on priorities etc. As mentioned above the units are somewhat generic and the other issue is that you or the player don't really have control of what the landed units actually contain. They will debark from the carrier and separate by type; all mobile personnel in one unit, all mobile vehicle in another etc.
2. Teleport: (The old fashioned way) is still very useful and quite easy. Set your units on the other side of the world, on a different side if you don't want the player to accidently see them. You can configure them to your hearts content and get them just the way you want them. Then set up triggers when the carrier unit enters an area, the specific unit teleports in (lua to change sides if needed) and you are good to go. This method is very controllable but takes a lot of decisions away from the player. Great for setting up a sandbox but also requires some very specific triggers and events.
3. Lua: Similar to Teleport but the units don't exist until the trigger is set off. The more you play with lua the better you will be at configuring the units, naming is easy, adding weapons/ammo etc can be tricky.
Each method has its place and usefulness depending on what you are trying to achieve. In some of my scenarios I use all three. Amphibious operations are complex.
CMO is a powerful game but not designed to replace something like Combat Mission: Shock Force, which I recommend if you want to get down and dirty playing USMC. So you should focus on what CMO does well, and that is giving the player decisions to make at the Joint/MEU Comd and Amphib task force level: What is the loading priority, outflow speed, distance ship to shore, what goes by helo or boat etc..
Good luck and if you run into problems this is the place to ask.