Hi,
HikaMarket redirect the "order_admin_notification" email to the vendors when a "sub order" is created. That's why you see the same content than the administrator received.
By unpublishing this email, it will be deactivated for both processes (email for HikaShop admin and emails for vendors).
There is special email for the order confirmation. We though redirecting the customer email to the vendor for "sub orders" but I was not sure that it is a good idea.
Sure the best is having special emails for vendors but the interface to modify HikaMarket emails is not finished yet.
For the moment it is possible to use a little plugin which would send emails to the vendors, it would keep the compatibility with updates without modifying any core file.
Best regards,
Jerome - Obsidev.com
HikaMarket & HikaSerial developer / HikaShop core dev team.
Also helping the HikaShop support team when having some time or couldn't sleep.
By the way, do not send me private message, use the "contact us" form instead.