The Chinese terms both use the character 阵 zhèn. Usually, the battle formations are called 阵 while the spell formations (the magic circle things which often use formation flags) are called 阵法 zhènfǎ. If you really feel the need to set them apart, then yeah, just call the spell formations "arrays". Keep in mind that the battle formations are often pretty magical as well. Like in Desolate Era where the battle formations usually involve thousands or millions of cultivators pooling their energy together and transforming into a single, giant being.