In a numeral classifier language, a sortal classifier (C) or a mensural classifier (M) is needed when a noun is quantified by a numeral (Num). Num and C/M are adjacent cross-linguistically, either in a [Num C/M] order or [C/M Num]. Likewise, in a complex numeral with a multiplicative composition, the base may follow the multiplier as in [n×base], e.g., san-bai ‘three hundred’ in Mandarin. However, the base may also precede the multiplier in some languages, thus [base×n]. Interestingly, base and C/M seem to harmonize in word order, i.e., [n×base] numerals appear with a [Num C/M] alignment, and [base×n] numerals, with [C/M Num]. This paper follows up on the explanation of the base-C/M harmonization based on the multiplicative theory of classifiers and verifies it empirically within six language groups in the world’s foremost hotbed of classifier languages: Sinitic, Miao-Yao, Austro-Asiatic, Tai-Kadai, Tibeto-Burman, and Indo-Aryan. Our survey further reveals two interesting facts: base-initial ([base×n]) and C/M-initial ([C/M Num]) orders exist only in Tibeto-Burman (TB) within our dataset. Moreover, the few scarce violations to the base-C/M harmonization are also all in TB and are mostly languages having maintained their original base-initial numerals but borrowed from their base-final and C/M-final neighbors. We thus offer an explanation based on Proto-TB’s base-initial numerals and language contact with neighboring base-final, C/M-final languages.