I never had any problems with gaesatae. Playing as the Arverni I fought a rebel army with 2 gaesatae, 2 mala gaeroas and 1 leuce epos 1 Brihentin. The gaesatae were on the left wing, so I pinned them down with my 2 sotaroas and sent my leuce epos (alright, so I had 4 of them) to their flanks to shower them with javelins, while tempting the gaesatae forward with my mala gaeroas. Meanwhile my 2 Botroas and 2 brihentin were holding off all the other units. The gaesatae attempted to charge my botroas' flank (all I had on my right flank were sotaroas who retreated as they charged, uncovering my centre) but by this time their 2 hit points had been worn down to one and they had lost about a fifth of their number. The 4 leuce epos hit them in the rear having exhausted their ammo about a second before their front ranks contacted the botroas, and the gaesatae routed without so much as even chewing up one single unit. A little anticlimactic, maybe, but I don't think I want to see the gaesatae acting out the horror stories everyone has been telling about them. But, seriously. Ranged attacks will rip them apart and dampen their morale. Anyone who tries to meet their charge with their own shock deserves what they get.