He uses Linbo Hengoku with 0 warning, 0 handsigns. Obito can't kamui what he can't see. Linbo hengoku just bashes him around constantly. If he warps behind madara, madara easily dodges him and limbos again. Obito's dying Low diff. There's no way he can counter Limbo with Kamui. That's like saying he can count ST or BT with kamui (the initial hits) when he can never see the invisible force coming.
Only way obito's winning this is if he ca nsit in kamui dimension and launch attacks somehow, but that's not manga supported.