Sorry. The legal limit is 8 passangers per carriage (no matter size of people or carriage). You may, however, take two carriages and have them stay together.
Shouldn't be an issue
I think there are 4 rows each seats 3 ppl.
The carriage I was on had four rows of seats that could fit 3 people in each row. As long as theres room, yes you should be able to!
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