It is entirely up to you whether you want to go first in a trade or use a mediator, the "2/3" rule is not an official rule.
However I do recommend using a mediator for trades as response time for a mediator request is usually less than 5 minutes and the process isn't complicated thus it's a good idea to request for one in-case you encounter a "who goes first" dispute during the trade.
Read about mediations here:
https://forums.d2jsp.org/info.php?p=11Feel free to send me a PM if you have any additional questions regarding mediations and trades.
This post was edited by Lionhearted on Jul 6 2023 12:41pm