To what extent were tactics the most significant factor in determining the course of two medieval wars?

Candidates will consider the merits of the proposition that tactics were the most significant factor in determining the course of two medieval wars. While the focus of the response must be within the timeframe of this topic, the two wars need not be contemporaneous with each other. The wars may or may not come from different regions. Candidates will ensure that consideration of tactics goes beyond description to explain how outcomes were affected. Candidates may focus on how fighting units on land or sea, such as light or heavy cavalry, heavily armed or more mobile infantry, or fighting ships, were exploited effectively, perhaps by achieving surprise or overwhelming numbers. For comparison, candidates may consider the roles of logistics, improved equipment, charismatic leadership or improved training. Each war may be considered separately or a thematic approach may be adopted.