Persians are, in my opinion, the most versatile civ.
The only overall tip for Persians that is different from other civs is to make use of paid labour from the War Academy.
Gold is gathered much more quickly and efficiently than food via caravans and paid labour really bolsters their economy due to how fast you can pump out villagers.
I'll go over the main army compositions and the best advisors for that particular composition.
Bowmen + Palintonon Comp
This is one of the best compositions for persians. Their bowmen take 1 population and have amazing range + dps. They are cheap and easy to mass and will shred practically everything.
Advisors for this comp.
Age 1 - Philon (This is standard for all comps)
Age 2 - Dumnorix/Perikles for better economic booms and easier early game. This can be replaced with Fletcher Gaiana in more slower paced legendaries where a fast boom is not as imperative. Gaiana sends their range into overdrive.
Age 3 - I personally prefer blacksmith Kosmas in conjunction with arrows of the ice king for a ton of snare. Onesiphorous is also fine. In quests where siege is not allowed, Sohrab is the go to for sure, i.e Marion/Asgard/Helheim etc.
Age 4 - Timo as you would expect for palintonons. If its a no siege secondary, then you can use Agamemnon for more damage on the bowmen.
Priest + Palintonon
The persians Magus is the best priest in the game due to the fastest rate of conversion. You can mass priests and have palintonons destroy buildings as all the enemy units get helplessly converted.
Advisors for this comp
Age 1 - Philon (This is standard for all comps)
Age 2 - Dumnorix/Perikles for better economic booms and easier early game. There's no need for any other advisors with this comp.
Age 3 - Mehrab has a lot of synergy with the magii and adds onto their conversion speed. Some people think it's overkill to use Mehrab but I prefer the super fast conversions. There's really no other strong contender.
Age 4 - Timo as you would expect for palintonons.
Immortals + Palintonon
Immortals are a very versatile unit. They're good into almost anything. The only downside of the immortals is the fact that they cost three different resources which requires often time extra villagers to support production. It requires putting a bit more effort into the economy unlike the usual, spam 50 caravans, then delete everything else way of playing.
Advisors for this comp
Age 1 - Philon (This is standard for all comps)
Age 2 - Dumnorix/Perikles for better economic booms and easier early game. There's no need for any other advisors with this comp.
Age 3 - Couple of different options here. Roham is my preferred option as it makes immortals train faster + have more health. You can also use Sophia for faster farming which in turn allows you to allocate fewer villagers to food, aka more population slots for military units. It's rare to use immortals to siege buildings, but if you do, then pamphilos would be the go to advisor.
Age 4 - Timo as you would expect for palintonons. If its an immortal only army, again, highly unusual, you can double down on infantry bonuses such as Theokoles for more health or again, agamemnon for health and damage.
War wagons + Palins
War wagons are a really fun unit and very effective especially against Greeks I find. You can easily do Paphos/soloi/cata etc with war wagons. Great, fun and underused unit. The big drawback of this unit is that in order to maximize their effectiveness and viability, you have to skip out on timo which is a huge trade off. This comp is best used in quests with sniping long ranged targets is not essential. Another limitation is ofc, the fact that it is a seige unit and as such cannot be used in a lot of legendaries due to the secondary objective restrictions.
Advisors for this comp
Age 1 - Philon (This is standard for all comps)
Age 2 - Dumnorix/Perikles for better economic booms and easier early game. There's no need for any other advisors with this comp
Age 3 - This can be Legia for faster seige training or onesiphoros.
Age 4 - Xerxes for the damage and movement speed boost to the wagons
All in all, the first two comps are the main and strongest comps for persians. There are other units as well although they are not as viable as the ones I listed i.e. massing cataphracts with Garshasp as 4th age advisor etc
Let me know if you have any questions.