Going back to your basic question about building around aid another, you might look at a halfling. They have a racial option that gives a bigger bonus when they aid. I believe it's called helpful.
Taking the adopted trait allows you to take a racial trait (and gives you that trait). So my human here has adopted.
And yeah, probably better to not multiclass all over the place. I'll look at that human fighter mix.
Here is what I had for the golden legionnaire
Half-elf cavalier (honor guard) 3/golden legionnaire 1/investigator (empiricist) 3 (Pathfinder RPG Advanced Class Guide 30, 100, Pathfinder RPG Advanced Player's Guide 32, Pathfinder RPG Adventurer's Guide 66, Pathfinder RPG Ultimate Combat 37)
LG Medium humanoid (elf, human)
Init +2; Senses low-light vision; Perception +16
AC 33, touch 15, flat-footed 30 (+12 armor, +1 competence, +1 Dex, +2 dodge, +6 shield, +1 trait)
hp 62 (7 HD; 3d8+4d10+20)
Fort +8, Ref +7, Will +5; +2 vs. enchantments, +2 vs. fear
Defensive Abilities trap sense +1; Immune sleep
Speed 30 ft. (20 ft. in armor)
Melee mwk rapier +5/+0 (1d6+5/18-20)
Special Attacks challenge 1/day (+3 damage, gain DR 1/- vs. target), tactician 1/day (Shield Wall, 4 rds)
Investigator (Empiricist) Extracts Prepared (CL 3rd; concentration +7)
Str 12, Dex 14, Con 14, Int 18, Wis 10, Cha 14
Base Atk +6; CMB +6; CMD 21
Feats Bodyguard[APG], Combat Expertise, Combat Reflexes, Extra Inspiration[ACG], Legionnaires' Inspiration, Shield Wall[APG], Skill Focus (Diplomacy)
Traits adopted, defender of the society, helpful
Skills Acrobatics -8 (-12 to jump), Appraise +8, Climb -9, Craft (alchemy) +14 (+17 to create alchemical items), Diplomacy +15 (+17 to gather information (You can use your Intelligence Modifier instead of Charisma)), Disguise +6, Handle Animal +6, Heal +4, Intimidate +10, Knowledge (arcana) +8, Knowledge (dungeoneering) +8, Knowledge (engineering) +8, Knowledge (geography) +8, Knowledge (history) +8, Knowledge (local) +8, Knowledge (nature) +8, Knowledge (nobility) +8 (+9 to checks relating to the nobles or politics of your land), Knowledge (planes) +8, Knowledge (religion) +8, Linguistics +14, Perception +16, Perform (sing) +6, Profession (teacher) +4, Ride -8, Sense Motive +8, Spellcraft +8, Survival +4, Swim -9, Use Magic Device +11; Racial Modifiers +2 Perception, honor in all things
Languages Abyssal, Aquan, Auran, Common, Elven, Hallit, Jistka, Osiriani, Shoanti, Skald, Terran, Thassilonian, Tien
SQ alchemy (alchemy crafting +3), authoritative command, ceaseless observation, defy danger (fear), elf blood, inspiration (8/day), intercept, investigator talent (effortless aid[ACG]), keen recollection, mount (Animal Companion), order of the black daimyo, sworn defense, trapfinding +1
Other Gear +3 benevolent full plate, +2 tower shield, mwk rapier, headband of vast intelligence +2, 3,413 gp
Alchemy +3 (Su) +3 to Craft (Alchemy) to create alchemical items, can Id potions by touch.
Animal Companion Link (Ex) Handle or push Animal Companion faster, +4 to checks vs. them.
Authoritative Command (+1/3 allies) (Ex) As move action, give you & allies bonus to attack, damage, saves, AC.
Black Daimyo's Challenge +3 (1/day) (Ex) +3 to damage target, -2 AC vs. others when used, DR 1/- vs. attacks from challenge target.
Bodyguard Use an AoO to use aid another to improve an ally's AC.
Ceaseless Observation (Ex) Use INT instead of CHA for gather information (+2)
Combat Expertise +/-2 Bonus to AC in exchange for an equal penalty to attack.
Combat Reflexes (3 AoO/round) Can make extra attacks of opportunity/rd, and even when flat-footed.
Defy Danger (Fear) +2 (Ex) +2 to save vs. fear.
Effortless Aid (Ex) Can use aid another as a move action, or use 1 inspiration for swift action.
Elf Blood Half-elves count as both elves and humans for any effect related to race.
Elven Immunities - Sleep You are immune to magic sleep effects.
Honor in All Things (1/day) (Ex) Gain +4 morale bonus to Save or Skill check.
Inspiration (+1d6, 8/day) (Ex) Use 1 point, +1d6 to trained skill or ability check. Use 2 points, to add to attack or save.
Intercept Increase AC bonus granted to ally from aid another by +1.
Keen Recollection At 3rd level, an investigator can attempt all Knowledge skill checks untrained.
Legionnaires' Inspiration (2 rounds, 3/day) As std act, grant all allies within 60' that can hear you a +1 morale bonus to AC.
Low-Light Vision See twice as far as a human in dim light, distinguishing color and detail.
Mount (Ex) Gain the services of a special animal companion.
Shield Wall +2 to shield bonus if adj ally with same feat has a tower/heavy shield or +1 for smaller shields.
Sworn Defense (Ex) Select a ward during a challange, sacrificing AC to grant bonus to ward's AC.
Tactician (Shield Wall, 4 rds, 1/day) (Ex) Grant the use of one of your teamwork bonus feats to all allies within 30 ft.
Trap Sense +1 (Ex) +1 bonus on reflex saves and AC against traps.
Trapfinding +1 Gain a bonus to find or disable traps, including magical ones.
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This one still has no combat capabilities, but seemed fun.
I'll look into that thing you posted