actually, here's an easier trick i learned as i played the final campaign.
i beat Francois' main island using only 3 ships, fully loaded and fully upgraded. i positioned the three close to the beachhead i want, clicked on the beachhead to build it with one of the ships, then as soon as i do that, i click on the other two ships and set their Demands to zero. as long as those ships are in range of the beachhead, they AUTOMATICALLY (albeit with a slight delay) fill the beachhead with soldiers as needed. this way, you don't have to manually transfer troops to the beachhead. you can then focus on the troops on the beachhead to attack the nearest barracks, and the other ships will refill the beachhead as needed. after getting a barracks, you won't need to send out other ships more. you can just wait on that barracks to fill you up as you need it.
of course, i managed to defeat this campaign by doing a rather simple money trick. after getting my population to around aristocrat level and getting my income to around 300+ with good island defenses, i just left it at a stable economy and income for a few hours. when i got back to it, i got around 40k, more than enough for me to go full blast with military production. i basically got a barracks running on every island worth building on and a port for refilling empty warships, and i conquered Francois' main island with ALL barracks running, leapfrogging Outposts as needed (they have HUGE attack range and can hold 50 soldiers). when i took the last barracks, i think may income was around -500, lol. ^_^ but yeah, that last part was pure joy, totally dominating his troops.
the reason why i had to keep all of my other barracks running was, even on his last barracks, Francois can still (somehow, maybe magically) produce three 30-man warship and pester one or two of my islands, which is annoying to no end. on this last battle, you really can't slack off on defense. --- PSzero FC: 3523-7125-5632, COD:MWM, MPH, FFTA2