Is the meaning of the noble verse: "And you delved as those who delved" the same as "You delved like their delving that they delved"?

The phrase "كَالَّذِي خَاضُواْ" (like that which they delved into) in the verse (And you delved in like those who delved) is a description of a singular entity, such as "like the group that delved," or "like the delving that they delved." It has also been said that its origin is "كالذين" (like those). Some are of the view that "الذي" (that which/who) is a relative pronoun used to express both singular and plural. Thus, "كالخوض الذي خاضوا" (like the delving that they delved) and "كخوضهم الذي خاضوا" (like their delving that they delved) convey the same meaning.