Your (by far) best troops are the phalangites, spearmen are only good for stopping the enemy for a short amount of time and for cheap garrison units. Phalangites are good against hoplites and cavalry (as they are spearmen), peltasts are ranged troops, but the command for ranged attack has to be given separately, otherwise they will try to fight the enemy in close combat. The scout cavalry is (like their name says) only good for scouting purpose, because reconnaissance is very important in this game - and to fight a single peltast unit if they are able to charge into combat.
If you know where the raids are coming from you can secure these paths by building watchtowers if there are any near that route (they will be getting destroyed consistently, but at least you know earlier if the enemy wants to raid your lands) and by garrisoning troops in cities near their raid routes. If they make a massive peltast spam you can buy a unit of Thessalian cavalry (with 20 guys in it) in Olooson and Larissa, the Companion cavalry is of course even better but you may not want to let them stay garrisoned for years in some unimportant city.
Unlike the real Macedonian phalanx the phalangites in the game can do a great amount of damage and even two brigades of hoplites can rout fighting a single phalangite unit if you know how to do it: Fighting in Hegemony is based on fighting infantry with infantry, light and ranged infantry with a good cavalry unit and cavalry with a fast battleline troop (infantry). Ranged troops are only good for supporting your other troops so keep them out of your enemies' range. Falling morale can have a couple of reasons: Firstly a combat unit losing very badly will rout. Every kill of the brigade will raise the morale a bit, every loss will diminish it a bit. Secondly a combat unit that was flanked by the enemy will have a steady loss of morale until it routs. Thridly troops lacking food will lose morale until it hits zero, then the first strike against this unit will cause the whole brigade to rout.
But you can also turn the tables: Flanked enemy units can rout with about 75% of their guys left minimizing your losses and increasing your number of slaves. Starving enemy units can rout without a single loss if shot at with peltasts or catapults.
And of course prepare your units before combat: plan the battleline, the position of your ranged troops and cavalry (normally hoplites ignore cavalry if they can fight infantry - leaving their peltasts without protection). Change to ring or convex formation if your infantry is outnumbered and try to avoid fighting "to the side" (e.g. if a hoplite brigade comes from the right, your guys are like a column and only four of them can fight at one time).
Lastly, if there are too many enemy troops on one pile (standing one in the other) you may wish to sacrifice your phalangites' general as he normally stands in the middle of the enemies and is attacked from every side and as he is the last one that will die (your soldiers will die instead even if they aren't attacked at all).
Thanks for the advice, and from everyone else. I have conquered Thessaly having left the North alone and now have conquered the Chalcidian League and some coastal Athenian cities that kept send triremes with raids always when a city runs out of food. Maybe I messed up going East as the rebellions due to lack of food is a nightmare and using up sheep as fast as I can get em. How do I get back on track ?, my empire is looking large dominating the centre of the map. Thinking of moving ever eastwards towards Byzantium as I know my history and know it's of great strategic value, especially as Athens is a great navy specialist. Any advice on losing cities to food and should I go east, or west ?, but west is a food nightmare as well.