Tips

[antisocialmunky]

Set your units in guard mode in two rows and wait them out. They'll get tired before you do and then its time to hack them to bits.

[pezhetairoi]

To the OP:

You really can't handle that with just 15 units. More cavalry is a must (though the Gaesatae also eat through cavalry, you can pound the Solduros with your AP Brihentin) and slingers also. Many, many slingers. 6 units would be a nice minimum. They have the longest range of any missiles ingame in the West, so that'll give you more volleys. Not to mention you can shave their armour from 5 to 2/3, and you get 30 shots at them instead of the regulation 15 of archers, and if your slingers are experienced, better still. Mori Gaesum, as mentioned before, or even Appea Gaedotos, will suffice too. Hold them with your Neitos and phalanx troops, then hammer them from behind with slingers for gaesatae and brihentin for solduros, while flanking with your principes. And pray hard your Neitos don't break before.

I think the intimidation effect of Gaesatae isn't cumulative, so 7 gaesatae in one place makes no more difference morale-wise than 1 unit present. So you don't have to worry about that at least. Let them pile on your phalanx. But not so deeply that some units can disengage to counter when you begin flanking/rearing.

[Morte66]

Get more missiles, you want a high attack value and lots of ammo. Then fight a battle of manoeuvre. Attack their army on the strategic map, so they will wait for you rather than coming at you on the tactical map. Send in skirmishers and cavalry feints to pull their army out of shape (not actual attacks), and lure off units one or two at a time then mob them. Lure their cavalry onto your spears.

Once your slingers/skirmishers can roam free without fear of cavalry etc, start long flanking moves to put them behind the nudists. If they turn to face the missiles, move some cavalry up close to them (without fighting) to get them pointed back the way you want. Then fire away, you won't see much effect at first as you take the first hitpoint but after a while they'll start dying like regular celts.

Do the closest thing you can to horse archer tactics, basically.

[Chris1959]

I agree with antisogialmunky guard mode is a very powerful tool, especially for the Romanii, your units will hang on longer against elites and buy time to get round the flanks and rear.

[marodeur]

My legions in the polybian era are always composed of 1 triari, 2 princeps, 2 hastati, 1 extraordinari, 1 roman/federati cavalry, 1 velites and one unit slingers (usually romans). I combine two of those legions with one general (together 19 units) and one merc/local troop, most often cavalry or archers. I can't guarantee victory against gasatae by doing this, but I win 2 out of three battles against gallic armies containing larger groups of Gasatae. Weaken them with arrows, stones and javelins, isolate them from other units and after this concentrate on them and attack them with cavalry-support. In my experience, it is most important to use the terrain to your advantage: fight downhill or hide in woods and lead them into a trap. Won't say it works like a charm, but it definitely gives you quite a good chance to win. And yes, it will cost you quire some lives. I hope to improve upon my kill-ratio with the use of new marian legionnaries.

[marodeur]

but I think it would be better - and more realistic - if really exceptional elite-units such as the gasatae (and the holy band phanlanx, the spartians, ....) would be restricted, so you could only have a certain amount of them at the same time.

[Morte66]

but I think it would be better - and more realistic - if really exceptional elite-units such as the gasatae (and the holy band phanlanx, the spartians, ....) would be restricted, so you could only have a certain amount of them at the same time.

I wonder if they could be made into non-recruitable but regenerating units (like the FM bodyguards). They'd be created by script, and if they get wiped out they're recreated at the capital with one man (to regenerate up). So the Gaulish factions get a regenerating unit of naked fanatics each, created at the capitals or wherever is appropriate. The KH get a unit of Spartans at Sparta (and not if they lose Sparta). The Maks get a unit of Hypaspists created at the capital, upgrading to two if they have 25+ provinces. Sacred Band at Carthage. And so on, as appropriate.

Or something along those lines...

[NeoSpartan]

but I think it would be better - and more realistic - if really exceptional elite-units such as the gasatae (and the holy band phanlanx, the spartians, ....) would be restricted, so you could only have a certain amount of them at the same time.

EB2

edit: (this is NOT a joke)