It is important is to get as many HH as quickly as possible as they are weak in small numbers. With headhunters you can creep very fast and more cost efficient since you spend less gold on healing items compared to grunt build orders. Its is possible to play this build in 1v1 in certain match ups like orc mirror, but it is not seen very often at all.
While TC is usually used in this strategy, due to the later altar you can actually get a tavern hero instead of TC if you want to. HH are complimented quite nicely by the TC aura and also stomp/wave. This build is most effective in team games 2v2, 4v4 etc due to the fact that HH provide military strength from early on and scale well though most stages through the game, especially thanks to their upgrade on t3 beserker form. Tauren Chieftain (TC) and Headhunters (HH) is an unconventional strategy to see in solo, but it does see some use.
