an application of each once? Btw my crypto is weak, but do answer this. if i apply a hash algorithm on something, it outputs a relatively small number of bytes.

an application of each once? Btw my crypto is weak, but do answer this. if i apply a hash algorithm on something, it outputs a relatively small number of bytes. Correct me if i am wrong but the strength of the hash lies in the fact that the input space is vastly huge so its difficult to create an input-output mapping for reversing the hash. Now if we use one hash over another, aren't we restricting the input space of the 2nd hash? Wouldn't that make it easier to crack the 2nd hash for this particular usage? And if my above statements are correct then the strength of sch a mechanism only lies in the strength of the first algorithm