Which Troops should you Send in a Battle March?[]
There are so many different types of troops that it can be confusing what a 'good' march is. Typically you should try to send a mix of Infantry, Bowmen and Cavalry. Focussing on a single type of troop is not an effective strategy. The mixture of different fighting techniques of the 3 main types work well together. Siege is very weak in the game and is not recommended in any battle march (unless you are sending troops to lose them, such as in KvK Excalibur Invasion).
A good march calculator can make this easier to work out. Please see for example https://englishtim.com/kingofavalon-calculators.
What Tiers of troops should you send? A lot of players will assume that a 'top-tier' march is the strongest as they have the highest battle statistics. However, there are diminishing returns using more of the same troop type. So, for a critical march you should have 6 tiers of troops (rather than 3) and for a mixed march you should have a mixture of all tiers of troops with a major focus on your top-tier.