it allows for the purchase of the Ajax's banner, level 8 armour and such
Master swordsman allows the purchase of the Dacian Falx? Light troops with both are killing machines doing over 100 points of damage.

No worries,

No point to upgrade past level 101, at level 100 you get a bunch of free upgrades to kit. Took a screen capture but it won't let me upload it.

Used the highest level of difficulty and only had two other units. Made the legate work for his money and whenever he did not need to live at the end he rarely did.

Is it possible?

I tried but the game would not enter the combat phase and would kick me out. I had to wait until after the last battle to see a final level and he was 186.

My best was trying to use only 2 units plus legate
I ended up with a level 186 legate (could only upgrade it 135 while playing though or it would freeze on me)
Light infantry with full kit upgrades levels 61 and 57.
1,115,360 fame

Some of the timed battles are tough in the middle.