No - as per the VIP400 user manual, continuous thermal withstand current is 1.3 times Nominal Current. So, if you choose 200A "CUa" sensors, this will be 1.3 x 200A.
Remark: VIP400 was designed to cover the most common setting ranges. If we consider fault levels in an MV network, if your transformer is supplying 400A per phase continuously, then it is not common that you would also require sensitivity down to 18A for the Phase Overcurrent trip setting. If the customer insists on both requirements (sensitivity down to 18A for Phase Fault and 400A continuous overload), then you cannot have both in one single VIP400 relay. You could choose 200A sensors in one panel to get 18A sensitivity. Then, for other panels with higher current where 400A continuous withstand is necessary, we can use 630A sensors (but have higher minimum Trip Setting).