Is it wrong to add additional premises?

When diagramming this question I created two premises and a conclusion, but my second premise and my conclusion formed a transitive relationship that created the flawed reasoning with the reversal. 1. NADM --> NDAC 2. NDAC--> Alex 3. Alex--> NADM For the second premise I used the Suff. and Nec. rule for "who" and read it as: "Alex is someone (nec.) who has clearly never done all he can (suff.)". 2 and 3 form NDAC-->NADM, so I eventually formed the chain correctly, but I'm wondering if in situations like this certain pronouns from the passage can be overlooked to save time?