It used to be stackable and it was better... Things like glacial rhino at the time saw a tiny bit of play in beasts because of it
I agree. Give it a 6 turn (3 Round) duration. Make it proc at the beginning of both players turns. This would mean one Gore would deal 5 damage unless cleansed. Make it stackable. Cost appropriately. A double attack from a Gore champion would deal the same amount of damage as DoT 2. Further attacks could go higher. Less attacks would be weaker.
Or consolidate gore with DoT effects in general. I mean DoT's are and have always been kinda strong especially on ranged units. Diseased (X): This unit receives 1 disease damage at the beginning of each turn. This condition lasts for X turns and is extended if stacked. In other words if a unit is diseased (4) and is attacked by a rabid champ which applies Diseased (3) the champion will end up with Diseased (7) instead of two stacks.