Rear suspension frame

[TheArf]

I have been cutting the steel for this during the week ready for tacking together. Looking at the book it says to tack together RS1, RS2 and RS3 and similarly RS4,RS5, and RS6 and then to tack RS7,RS7a,RS8 and RS9 underneath. Now my question is should you fully weld the top face of say RS7& RS8 and the underside of RS4 & RS6 to achieve weld on all four sides of the joint, when placed one on top of the other. Dont know if I have explained myself properly

many thanks