It’s one of those “you pay your money, you take your choice” kind of things. Go with one, or go with the other, but they will lead to distinct things.
Anyhow, we don’t even need a Passover Haggadah in order to notice implausible things in the “wine is the literal blood and bread is the literal body” reading. But it certainly clears up the context very well. The extant Haggadah dates back to gospel times. That said, the act of ingesting the symbols is also expected to accompany an act of spiritual recognition and acceptance and appreciation of the symbolized things — unlike the items symbolized by the other elements of the Passover seder, the spiritual body and blood are right here, right now. If it doesn’t accompany such an act, God will chastise for abusing the purpose of the symbols.
You mean like eating Maror, a bitter herb, symbolic of the bitterness of slavery, and green vegetables in salt water, symbolizing the replacing of our tears with gratitude, etc. https://en.wikipedia.org/wiki/Haggadah