The Guest Assistance Cards are normally given for a party of up to 6 (5 plus the person with a disability).
The CMs can make exceptions, but a lot depends on your party. If it is a party of 2 parents and 5 kids, they won't say, "sorry, 6 is the limit". If you have a party of 10, chances are very good that they will tell you the limit is 6 and not give a card for more than 6.
There are times that even if you have less than the number on the card, they will ask you to split into smaller numbers. When that happens it's usually because the space for people with special needs is limited or there are already (or they expect) the space to fill with people with special needs. When that happens, they often limit to the person with a disability and 1 or 2 of their party to accompany them. This has happened to us at times, even in situations where our total party was only 4. It has happened when there were already several parties waiting for the show to begin and to accomidate more people who absolutely needed to be in that quieter space, they asked that only one person stay in that area with the "special needs" person. It's also happened to us in the Special Needs parade area.
If your group is large, you may find it is easier to split into smaller groups and meet up later for meals, etc. Trying to keep a large group (8 or 10) together all the time is really difficult even if no one has any special needs.