Really, this achievement is only dictated by luck if you let it. Some social engineering will get you this title. I won this achievement 2 weeks in a row, for the rod and the trinket...and this was back in the day when raids of 40+ ally would camp it. So I am tired of hearing people on this board cry about RNG and luck. You make your own luck in this game. It was no luck that my 1st 2 weeks doing this that I got it both times.
1) Pick a side/path and keep to it. Practice your route before the contest, as all the pools are in the same place, just replaced by Tastyfish.
2) Get about 10-15 friends to come with you. Offer to pay them each 100g or so for their 40 min of time. Trust me, this is how I won my 1st two weeks doing this achievement.
3) Send 2 groups of 3-4 roaming every coast, killing every ally they find. This is your gank group. It will immediately weed out some of your competition.
4) Keep 2 with you as bodyguards. Never stop to help them kill someone, always fish. Have a pally be 1 of your bodyguards, for mount increase speed aura.
5) Send 1 group of 2 people as your "spotters". They run up and down and spot pools for you. It is best if they are male tauren. If any ally come by, kill them. If any horde come by, get your 2 tauren friends in the water, jumping up and down, making it near impossible to click on the catch for the competitor.
6) Carry Elixir of Water Walking with you so you can easily cross any water obstructions and easily maneuver to get any pool. Or have a DK be one of your bodyguards.
7) Lastly, don't bother with setting your stone to BB. Have a summon team consisting of a Warlock and 2 friends be ready right @ the turn in. Not only do summons have no cast time, but it will put you closer to the turn in. This contest is ALL about using every last second. When you are at around 35 tastyfish, have them summon you, so that the absolute second you get all 40, you can click accept on your summon and turn it in.
Thats about it. You follow those 7 rules exactly and I promise you, you will win whenever you want to win. You may think that some of my tactics are semi-dick moves. But hey, I have been known to go to STV and win the contest weeks in a row for no better reason than to stop people from getting their achievement. :-D