Hey I am really glad other people are seeing the amazing awesomeness of the Samurott tank! I looked through your deck list and would like to compare mine and offer suggestions.
Here's mine as of today:
4-3-4 Samurott
2-1-2 Feraligatr
1-1-1 Politoed
3 Manphy
1 Suicune Entei Legend
2 Rescue
10 Water
1 Fishermen (looking for a way to add 1 more)
2 Elm's
3 Pokemon Collectors
3 PONT
3 Juniper
2 Interviewer's
1 Twins
1 Flower Shop Lady
4 Rare Candy
4 Pokemon Communication
I use the legend for a bit of sniping power, maybe to take out an Emboar to ruin a Roshemboar's play. Or maybe even a ninetails or noctowl.
I just put the politoed tree in today, I haven't tested it yet but I have seen it work amazingly well in the "wallord"(4-4 Wailord) deck. It grants free retreat cost for a water deck.
I HIGHLY suggest Manaphy because of the free retreat cost, hand refresher, and the ability to do 20 damage if needed. My league is dominated by the cleffa brigade and I need something that can match their speed without going to sleep.
Smeargle is something to stay away from because if you read it's power, you MUST use a supporter from your opponents hand if they have one. SO if they ONLY have a Juniper, you have to discard your hand which could potentially ruin your game.