I do think that the death of Titinius and Cassius is a parallel of Romeo and Juliet, just like Horatio trying to kill himself upon Hamlet's death. Opinions?

Titinius and Cassius are a bit more of a parallel than Horatio and Hamlet, because one of them killed himself after thinking the other one is dead, and when the other one found out he killed himself too.

With Horatio and Hamlet, Hamlet was actually dying and Horatio wanted to join him. Hamlet told him that he has to live on, and so he did. So it’s not really a great parallel, but I can see why people would compare the two scenes.