The problem with using scouts as Franks is that they strategy is very predictable and you may find your opponent walling early or making plenty of spearmen to defend with. Also, you can afford to attack the villagers in a manner that is less hit and run because the villager will not cause much damage to Frank scouts. They do need bloodlines to achieve this though. This is due to their civ bonus of taking 50% less bonus damage. The only civ that can 1v1 a spearman is the Sicilians. Because of the extra HP, Frank scouts are a little more resistant to spearmen however you will still need to be very careful against them and only attack them if they are alone. If you’re lucky your scouts will reach the enemy base before they have had chance to fully wall. The extra HP that Franks have for their scouts results in a really strong rush. Taking advantage of the Franks faster berry gathering speed, and the free farm upgrades, Franks are able to advance to the Feudal Age 2 villagers sooner than the standard Scout Rush meta.
The AOE2 Franks Scout rush at 19 population is one of the best scout rushes in the game.