How do you get into the legion camp on fortification hill when you have legion infamy ?
Violently.
OT: I find a Frumentarii makes more sense as a playthrough than a Legoinaire, personally speaking. Unarmed is possibly the most powerful combat skill in the game, and arguably the most versatile for a stealthy playstyle, so tag Unarmed. Unarmed depends on Endurance, and Survival is also benefited by Endurance, so tag Survival. With Survival tagged, you have no need to tag Medicine, so tag Sneak instead. Sneak depends on Agility, which should be set to 7 so as to provide Sneak with a good value and unlock the Slayer perk later in the game. Now, with two tag skills depending on Endurance, Endurance should be 8-9 which will also allow you to take advantage of implants.
Just my idea of a good basis for a Frumentarii.
-Nukeknockout