On this, there are more transport types than just the Manticore if the last backer build is anything to go by. There are/were factional transport types at the very least which offer larger capacity which also means you can bring more troops with you.
Edit: If anyone is curious to see what kind of things backers were discussing as the forums still remain as they were two good examples can be found here:
Warning, Yokes really went to town on their feedback on that 2nd one and it is a lot of reading.