Halflings had really good basic infantry I remember having beaten an magi at impossible without boosts with only the two initials halflings. This race does not needs high tier units you could just have some buildings for improving the base halflings you train for example an building who improves the luck bonus and one who allows halflings to get one level higher (stack-able with crusade and war lord for having ultra-champion halflings).
And with those high level halflings you would be able to beat high tier unit.