My opinion is you should take the SCWCD first and then give the SCBCD next. SCWCD concerns with servlets and JSP and JSTL with , web security and some patterns, in the exam objective. SCBCD concerns with EJB. Since servlets and jsp are used to generate dynamic web pages primarily and still developing web pages is a thing that every web developers would be starting with, you should acquint yourself with it. What better ways to do that, than first giving SCWCD a shot?