I see no contradiction here:
Lao: ຊ (ຊ ຊ້າງ)
is a direct equivalent of
Thai: ช ช้าง
This even includes the meaning of the verbose name of the consonant ("an elephant").
Many other words "behave" the same, they preserve their written forms but pronounced according to each language's standards:
- "nation" ชนชาติ
[tɕʰon tɕʰâːt] - ເຊື້ອຊາດ
- "win" ชนะ
[tɕʰá náʔ] - ຊະນະ
- "help" ช่วย
[tɕʰûaj] - ຊ່ວຍ
Phonetically, the Lao consonant may have softened a bit comparing to its Tai (not Thai) origin, resembling (IMHO) the Chinese consonant
[x], as in "小"
...and not “ຈາ” (chaa)?
[tɕo tɕɔ̏ːk] is a totally different consonant:
- It's unaspirated in Thai, and probably it was so in proto-Tai languages; This alone is a dramatic difference;
- Mid class (versus ຊ Low class), the whole set of words will require different tone marks;
- It's a direct equivalent of Thai จ จาน
P.S. Latin transcription may be a false friend as it suggests no difference between:
I would rather write
chh if I could.