I suppose but u also have to take the plethora of words that exist in one and not the other and different dialects E.g the word for family is “parivaar” in hindi and “khaandaan” in Urdu God is “bhagwan” in hindi and “Rabb” in urdu etc etc I’m not sure about Hindi but I think it derives from Sanskrit. but Urdu was called “Rekhta” before as it’s parent language . The word Urdu comes from the Turkish word for army “Ordu”. Urdu was formed after an amalgation of Arabic and Persian and over the years as soldiers from different ethnicities came under one banner in the subcontinent it picked up vocab from old Hindi as well and due to the centuries of living along side Hindi speakers, alot of words are understood between each other. If someone was to speak Rekhta or even “pure” Urdu today as how or is in old poetry, as it was in the beginning, I’m sure no hindi speaker will understand and even modern Urdu speakers will take a minute