I am attaching a shelf on a nightstand to 2 supports. The shelf will be attached with 2 vertical Dominos on each supporting piece. Both the shelf and supports are 3/4" white oak. A 5X30 Domino would go approximately 9/16" into the 3/4" thickness of the shelf. Would it be better to use a #4 Domino? It would not extend into the shelf quite as deeply and, since the Dominos are really only holding the shelf in place rather then supporting the shelf, would the #4's be sufficient? In addition, the glue joint of the shelf to the supports is edge grain to edge grain, so that alone would be lending strength.