I agree, if you walk confidently like you own the place but respecting their boundaries and they leave you alone. Show any sign of fear or "shadiness" they can perceive that.
I used to walk around no problem until my German Shepperd (Big boy maybe 55-60 Kg) got out to walk with me... then every dog would try to challenge him and he would put them in their place (He's so much bigger and stronger I'm not worried about him). Is impossible to walk with him because all the other dogs come at him aggressively and although he stays with me if you get to close he will bite. But now the Soi dogs associate me with him, so they bark or challenge me, guilty by association.
There is a huge soi dog problem in Thailand. No owners, pack mentality, and the locals don't care. Introduce dangerous breeds to the pack and accidents are bound to happen.