Choose pikemen if you expect cavalry from your opponent or if you want to kill a lair. If you think you can defend a fifth farm with only Barracks units then you can delay the 2nd Barracks/Archery Range/Stables to increase your income. Instead of a 2nd PB you can also get a hero of your choice, e.g. Eowyn vs. Dwarves.
This riskier build sacrifices economy for aggression. In order to take advantage of it you have to make your opponent's economy weaker than your own with good harassment, or stay ahead in army size to keep him busy while you expand.
This build relies, as with all other cavalry starts, on the guaranteed damage and protection that comes with early horsemen. If you're playing against a faction that is unlikely to get pikes out very fast (Mordor, Gobs) you can build a third farm before your Barracks. To speed up your transition into infantry you can also delete your Stables after the first Knights have spawned. This fast switch is very likely to overpower you opponent since he will weaken his unit composition with safety-pikemen against the Gondor Knights.
Greedy Start
oror Farm->Farm->Farm->Barracks->Farm->SoG->Farm->SoG->Archery Range or Stables->Rohan Pikemen
This build is a greedy variation of the standard start in which you build your 3rd farm before your Barracks, and your 4th farm before your first SoGs. You're very likely to get away with this in most situations, starting off with a good eco; but your aggression will be delayed as well and will be more exposed to harassment yourself by offering your opponent a lot of targets early on.
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