@Cards Users we also have a couple notes and questions to answer. The op will be updated with this info too.
Firstly, in a 3 way or anything more than 2, each trade is counted as one trade. So if you do Miyeon 4 for Somi 2, then trade the Somi 2 for Jonghyun 1, that's 4/10 used up that day.
Secondly, trades count differently based on who's posting. For the poster of the original trade, the trade counts when it's posted. For the person agreeing, it's counted as when the person agrees. So you can have a trade counted on different days for the different participants, as long as neither one exceeds the 10 cards per day. If the agreeing person has more than 10 already, they will have to reagree the next day. If the person posting has more than 10 the trade will need to be reposted the next day, but the person agreeing will be able to use the previous agreement as long as the repost reminds the team of the agreement being done already.
If anyone else has questions, feel free to ask