The Alma plans mention shock loads on the servos. I use Hitech 82mg, (micro, metal-gear) servos on my boats. No stripped teeth yet
. Nylon gears will strip, been there done that.
I have 2 schooners (not Alma). You will find it easier to tack and wear if the mainsail is on a separate servo, rather than controlling it simultaneously with the foresail+jib, as shown on the plans. The big advantage of a multimasted ship is the ability to use the sails as "air rudder." For schooners, in particular, if the sails are fighting the rudder, then the sails will win. One schooner modeler (on another site) who controlled all his sails on one servo (per plans, different design) quit sailing. He kept ramming into the stone wall surrounding the park's pond. Turns are just very slow if performed under rudder only, he found. He's thinking of redesign of his sheeting scheme.
Differential sheeting, that is, controlling the sheets of the sails fore of the CLR (center of lateral resistance) separately from the sails aft of the CLR, is the key. To bear off, slack the mainsheet: the sails fore of the CLR will automatically turn the bow away from the wind. To head up, slack the foresail and jibs: the mainsail will automatically make the hull turn into the wind. Tacks and wears are much easier to complete with differential sheeting. I use differential sheeting on all my boats.
There seems to be plenty of room to add a 3rd servo below decks on the Alma, one nice advantage of the scow-type hull.
Sail arm servos have proved sufficient on all my sailboats: Pamir, 4 masted barque; Aldebaran, fore&main topsail schooner; BottleBaltimore (foretopsail schooner); Sandbagger (gaff sloop). I've not had to go to the expense of winch servos. Winches are nice, but are more sensitive to slack&snarls. John Dowd has mastered the winch technique for schooners, though; his Bluenose is magnificent
.