Don't have any ideas. But I do have one question.
Who is going to go aloft and furl and unfurl those eight square sails?
Are you going to have a paid crew?
Maybe a fore and aft sail on the mizzen will make the ship easier to work. That can be in place of the two square sails there.
Although square sails lasted well into the 20th century, they were used almost exclusively on deep sea vessels which sailed almost exclusively downwind. It is on that point of sailing that they excel. Other than that, they kind of suck. I used to joke that sailing dead downwind was for racers and for square riggers. I rarely did it with my own fractional sloop. I almost always went downwind on an angle. That way, the differential wind pressure on the sails tended to steady the boat against rolling.
I recently toyed with the notion of a square rigged dinghy. It had only one sail. But to get it to sail upwind tolerably well (120 degree tacks). I counted eight lines to control this sail. It would have been a real challenge for one person to handle. The top of the sail had two sets of brace lines, one for downwind sailing and one for upwind sailing. The upwind sailing set sheeted close to amidship, and the downwind set sheeted very far aft. The bottom of the sail had a pair of sheet lines, which led far aft, and a pair of tack lines, which led close to the bow.
Attached below are two simple sketches of what I came up with. The upwind brace lines are not shown, as they could be possibly done without.
View attachment 192504 View attachment 192507
As I hope you can see (in the 2nd attachment) how far aft the windward brace is sheeted. It looks like a backstay. This puts it under tremendous stress. By putting a second set of braces amidships, I hope to get a better sheeting angle for it.
I personally believe that the dipping-lug sail, popular on both sides of the English Channel during the days of sailing workboats, evolved from the square sail, rather than the Mediterranian Lateen sail. I think the process started by setting a square sail fore and aft, rather than athwartship. This would eliminate a lot of control lines. After that, I believe they made the luff somewhat shorter than the leech. I've seen pictures of such dipping-lug rigs where there is as much yard infront of the mast as behind it. And the sail looked almost square. The only problem with that scheme is that the yard had to always be on the downwind side. This meant that it had to be 'dipped' from one side of the mast to the other every time one changed tacks.