Thejoltess makes a very good point: The priority numbers are meaningless unless you're selecting multiple events for the same time. That's the only time they matter.

If your friend goes through the wishlist processing first and buys their events, and bought you a ticket, you will get an e-mail that says "Friend bought you a ticket!". Same thing will happen if you happen to be through the processing first.

What will then happen is, whoever hasn't had their wishlist processed will not be able to get the ticket, because they already have a ticket purchased for them in that time slot. It will show up on your list as a conflict. It doesn't mean you don't have the ticket though. 

The only time this causes a real headache is, say the event you and your friend want to do is Thursday at 10 AM and it's two hours. Say there is another event at Thursday at 11 AM that you want to do if you don't get the event with your friend. Both you and your friend select each other and select "Only get selected tickets if ALL selected are available"

You process your wishlist first and you didn't get two tickets to the event, so your list skips down to the other event at 11 AM. Your friend's list goes to get processed but now 2 tickets have appeared for that event, but now your friend can't buy them because you already have an event in that slot because it overlaps.

If neither you or your friend have another event that conflicts with the L5R event, the best odds to get them is for you and your friend to put the event both on your list and select purchase for friend.