There are usally 2 ways to get inside Horde base. 1st being the tunnel, 2nd the ramp east of the tunnel. But there is a 3rd way.
South of Horde graveyard there is a mountain. If you walk there against the mountain (till you cant go further up) and then walk carefully right you are on top of it and can head to Horde flag room. Needs some pratice. This way you can buypass enemies who camp the tunnel or the ramp and get rid of enemies who dont know how to exploit this. Can also be used to easily get inside Hordebase while your group kill them near the tunnel.
South of Horde graveyard there is a mountain. If you walk there against the mountain (till you cant go further up) and then walk carefully right you are on top of it and can head to Horde flag room. Needs some pratice. This way you can buypass enemies who camp the tunnel or the ramp and get rid of enemies who dont know how to exploit this. Can also be used to easily get inside Hordebase while your group kill them near the tunnel.