What are you talking about? Do you understand why China needs a base or more in ASEAN region?
Apparently not.
Your arguments so far don’t make sense to me, hosting H20’s, PLARF, or floods of Diesel Subs as you suggested is just not realistic imo, why would Cambodia agree to that? Have you considered Cambodias point of view at all? Or ASEANs? Or Chinas past modus operandi?
My arguments:.
1. There is no threat in the Gulf of Thailand.
2. A strong Cambodian Navy can defend its maritime territory by itself.
3. China can already cover those waters with rockets and subs and god knows what else.
4. It’s adjacent to the SCS, which China can easily deploy from, doesn’t even need a support ship.
5. It’s in the first island chain, surrounded by friends and neighbors.
6. It doesn’t protect anything.
7. It would just be an easy to target for nearby western forces, easy to destroy or blockade.
8. China said they are not.
9. Cambodia said they are not.
10. Geography, the Thai ismuths blocks access to the Indian Ocean anyway. China can’t sail through it or fly over it, they might have US SAMS deployed there.