What semantic notions underlie 吳 (shouting) with 夨 (man with tilted head)?

Question

Reading 誤's etymology spurred me to read 吳's etymology. Shouting doesn't require you to tilt your head, so why was 夨 used? Why not just use 人?

Glyph origin

Ideogrammic compound (會意): 口 (“mouth”) + 夨 (“man with tilted head”) – to speak loudly.

Definitions

1. † to speak loudly; to shout
2. † big
3. (historical) (～國) one of the Warring States
4. (historical) (～國) Eastern Wu, one of the Three Kingdoms
5. the territory those states held, around the Yangtze delta

6. Wu; the Chinese dialects of that territory, including Suzhounese and Shanghainese

   ⇒ 吳語

7. A surname​.

   吳作棟 / 吴作栋 [Min Nan]  ―  Gô͘ Chok-tòng [Pe̍h-ōe-jī]  ―  Goh Chok Tong (Singapore's second Prime Minister; currently Emeritus Senior Minister)

8. (～港) a harbor in Hiroshima Prefecture, Japan

Answer 1

This question is actually a good example of why Ancient Chinese scribes cannot keep on drawing pictures to represent words. They can avoid similar-looking or similar-meaning character components to a degree to distinguish between different words, but at some stage, it will become easier to incorporate a component which refers to the sound of a word rather purely relying on the meaning of a word.

Person (人) + mouth (口) has already been used for the character 「兄」.

商
甲

甲2292
合集20014今
楷


　

Front view of a person (大, no tilted head) + mouth (口) has already been used for the following character:

商
甲

後2.18.7
合集3028
隸定