The development team at Total War: Rome Remastered have created a let's play video on the Gaul faction and shows off the rush to conquer Rome in just 30 turns. It is doable but very difficult considering the early game Gallic units have very little armour against the basic but armoured and disciplined Roman units. Gaul has an excellent strategic position in which to do this but can be vulnerable from an attack on all sides with Britannia in the North, Spain in the West and Rome from the South, the lands to the East are contested but that's usually when stronger factions start to take a grip on them. So lot's to do and lot's to decide on, the condition however is to conquer Rome in 30 turns so we're not worried about the Britains or the lands to the East.
In the video it shows the situation you are faced as Gaul, the Spanish lands have lots of silver which is incredibly lucrative to fill up your war chest. It also shows off the role of the new agent unit, the Merchant. The Merchant can be built from the market building and other similar buildings related to trade and commerce in other factions. They can be used to increase the value of trade between factions you have got trade rights with or used to monopolise certain resources that only enables your faction to trade with them. This can be crucial as factions start to explore and gain trade rights across the map you may want to utilise your merchants to ensure your enemies or other economic rivals do not gain valuable resources for their faction development.
Watch the developer gameplay overview below and see for yourself the new gameplay and dynamics that you may face if you play as Gaul: