Is this Hinduism

Lately i came across the rituals involved in Ashvamedha as said by rig veda.I was surprised/shocked to read how they perform the ritual , listing a few from the above said wiki link below.

After this, the horse, a hornless he-goat, a wild ox (go-mrga, Bos gavaeus) are bound to sacrificial stakes near the fire, and seventeen other animals are attached to the horse. A great number of animals, both tame and wild, are tied to other stakes, according to a commentator 609 in total (YV VSM 24 consists of an exact enumeration).

Then the horse is slaughtered (YV VSM 23.15, tr. Griffith)

Steed, from thy body, of thyself, sacrifice and accept thyself.

Thy greatness can be gained by none but thee.

The chief queen ritually calls on the king's fellow wives for pity. The queens walk around the dead horse reciting mantras. The chief queen then has to mimic copulation with the dead horse, while the other queens ritually utter obscenities.^[2]

On the next morning, the priests raise the queen from the place where she has spent the night with the horse

The horse is dissected, and its flesh roasted. Various parts are offered to a host of deities and personified concepts with cries of svaha "all-hail".

The priests performing the sacrifice were recompensed with a part of the booty won during the wandering of the horse. According to a commentator, the spoils from the east were given to the Hotar, while the Adhvaryu a maiden (a daughter of the sacrificer) and the sacrificer's fourth wife.

Doesn't it look barbaric and i am sure that these are not definitely in line with todays ideals and ideas of Hinduism.

I really fail to understand and iam looking out for some one who can answer the

Why the heck they do this?

Is this the misunderstood version of the ritual?

Rig is all abt such rituals ?

So, it could have made sense at that point of time?

So, when does Hinduism's civilized version released and who released it ? Adhi Sankarar ?

So is it true that he was actually influenced by the ideas in Buddhism (Samanam) and changed Hinduism that way ?