The top tier troops are no longer upgradeable to.In order to create such you must meet certain requirements, and they cost money, and then you must spend time to make them.

• 顶级部队不能直接升级得到，城镇要达到一定级别，还要花钱和一定的时间，才能把倒数第二级的士兵升为顶级兵种。