Complex sentence: This type of warfare can be seen the early stages of WWI, where there was still strict adherence to drill and discipline of formation and uniform, but the dependence on artillery and firepower to break the stalemate and move towards a pitched battle.
Split into simpler sentences: This type of warfare can be seen in the early stages of WWI where there was still strict adherence to drill and discipline of formation and uniform. However, there remained a dependence on artillery and firepower to break the stalemate and move towards a pitched battle.