There may be some misinformation or just missing information there.
Upgrades matter during battles.
The most important is the ship level. Level affects ship hit points and also how hard each cannon shoots.
For each cannon shoot, upgrades interfere that decide where a cannon fire was successful or not.
Note that the max number of cannons each ship can fire in one round, is the (cannon it carries) / 2.
To determine if a cannon shot successfully landed, we first have the attacker ship which has an attack roll. Attack roll is determined by bronze cannon, double hammocks, crew and some luck.
In response, the ship that is about to receive the attack, rolls an armor class which is determined by copper plating, cotton sails, ship speed and some luck.
Who fires first is decided by the ship speed.
Ship Speed is a measurement of basic speed data plus cotton sails upgrade.
Every ship starts with 5 attribute points. You gain 3 to 5 more for each level upgrade.
From:
http://s2.piratesglory.com/index.php?page=ship&id=XXXXX (where XXXXX is the ship ID number)
Round Shot: Better round shot means better ammunition. It increases the total damage dealt.
Bronze Cannon: Bronze cannons improve ship shooting accuracy. It increases probability to hit.
Copper Plating: Copper plating helps your ship turn faster. It increases probability to avoid each hit.
Iron Scantling: Makes the ship hull more resistant. It increases the damage absorbed vs total damage received.
Double Hammocks: Double hammocks improve crew health and morale and is in direct connection with ship crew number. It increases propability to hit.
Cotton Sails: Cotton sails make your ship sail faster and is in direct connection with the ship speed. It increases probability to avoid each hit.
You may have noticed that there is no reference to Round Shot or Iron Scantling at the first address.
Also, if you spot things better than I do, you will have noticed a typo on the Double Hammocks line at the second address. (propability) The spell check in the forum found it.
But anyways, I have always thought that If a player was impatient, he would max out:
Round Shot, Bronze Cannon, Double Hammocks, Cotton Sails, Iron Scantling and Copper Plating in that order
while someone who thinks endurance is the key would go for:
Iron Scantling, Copper Plating, Cotton Sails, Double Hammocks, Round Shot and Bronze Cannon in that order.
One set of information implies that Iron Scantling and Round Shot don't matter. I thought Iron Scantling would play a role in armor class or serve as a hitpoints multiplier and that Round Shot would serve as an impact multiplier.
I know you are busy making Pirates Glory amazing but could I get just a little clarification on this. I am working on retaliation and I want to get it right.
Sorry about all of the posts today. I've just been a little hypersensitive and sleepless. I hope you understand that my intentions are to be malicious...
I mean helpful. 
