…y - less-than/greater-than comparisons on enum int equivalents are not always clear.

…mostly infantry-related. General readability improvements, such as re-sequencing switch bock to group related roles, replacing array index calls with named variables, and descriptive commenting. Updated tests to better reflect current range of units and capabilities.

… be easily excluded from use in combat roles.

…ts without the direct FIRE_SUPPORT or SR_FIRE_SUPPORT role

…pment checks and role

…, BA_CARRIER roles