Robin has proven himself capable of soloing the other four super powered members members of his team and Slade has consistently proven to at bare minimum be Robin's equal. The assassins, on the other hand, may have some skills that require suspension of disbelief, but none of them are anywhere close to being able to best superhuman opponents. Long story short, Slade. Easily.
Never let anyone else define you. Don't be a jerk just to be a jerk, but if you are expressing your true inner feelings and beliefs, or at least trying to express that inner child, and everyone gets pissed off about it, never NEVER apologize for it. Let them think what they want, let them define you in their narrow little minds while they suppress every last piece of them just to keep a friend that never liked them for themselves in the first place.