Two units garrisoned and providing 2.5 time the damage of a single unit would be great, I think. But this is true only if that was used for combat. If chariots were only used for swift transport, we should allow more units (otherwise it'd be rather useless in the game (these are typical sacrifices of historical reality towards better gameplay). Scenario: You brought 10 chariots to the front, each having 5 passengers onboard. Let them disembark and fight while the chariots go back to provide more relief forces. Effective if the chariots were significantly faster than walking troops. Not sure if this is too much micro?

The thought occurred to me that after the implementation of Marian Reforms the three Roman heroes are now out of their time frame, so what about replacing them with three new heroes like Julius Caesar and Pompey and one other from that era?  If there is a proper place to put ideas please point the way as I am currently unsure if it should be community mod or some other place

it is also quite common to use one of your starting infantrymen to scout. It kind of depends on how worried you are about getting stomped by a big rush.

The standard game starts with a scout. If you want to scout, you're free to use it. You can always make another cavalry unit and use it to hunt.

main reason for adding to sparta and athens is becasue early on they were really known for using a lot of horses.  You can scout pretty well with cav in 0ad

Oh - and I also believe, Petra AI should need scouting as well and not rely on a revealed map as it is currently the case (possibly not easy to implement at all).

Sounds like a good idea! Scouting can be useful not only to find out where everyone resides. I have also successfully used scouting in the first minutes of an SP game (nomadic mode) to attract adverse citizen soldiers into a trap (one by one) so they were not able to establish their CC.