A country highly populated by Buddhists is one matter. The fact
is, before Buddhism becomes the dominant religion in Thailand,
Brahmanism is the dominant religion (I think). Brahmanism in fact,
has highly influenced Thai Buddhism (e.g Thai Amulets derived from
Brahmanism). Some practices by certain monks that are considered
superstitious other non-thai buddhists. However, this is not to say
that Thai Buddhism is not as good as other types of Buddhism, in
fact most Buddhist sects are more or less influenced by their local
culture and traditions. Most important is that their Dharma remains
intact and doesn't lose purity.
I'm not very good at Hinduism, so I'll quote from a website:
Looking at the four directions, the four faces of Brahma
symbolize the four Vedas as well as the cardinal points of the
compass.
The scriptures of Vedas (and many other hindu texts) are
rejected by Lord Buddha Shakyamuni. Buddha Shakyamuni had many
instances of meeting the Brahma, in fact, it was Brahma who begged
Buddha Shakyamuni to teach the dharma. However, this Brahma is also
under the illusion that he was the Creator of all. Buddha had dealt
with Brahma and his ideology several times in his scriptures. There
are also many interesting stories revolving the Brahma.
The stories of a Buddha going to teach a brahma take place on
the plane of Maha Brahma, the third of the fine-material planes
(No. 14). Many people worship Maha Brahma as the supreme and
eternal creator God, but for the Buddha he is merely a powerful
deity still caught within the cycle of repeated existence. In point
of fact, "Maha Brahma" is a role or office filled by different
individuals at different periods.
The Buddha has directly seen the origins of Maha Brahma and
understands what it requires to be reborn in his world. In the
Brahmajala Sutta (DN 1) the Buddha describes how a supposed Creator
God came to believe himself omnipotent and how others came to rely
on his sovereignty.
http://www.urbandharma.org/udharma/devas.html#ch2
