As a technical, and perhaps opinion based, question.... If I use two sawhorses( Heavy Duty) and place TWO 2x10's as support structure across spanning the gap between the two and then placed a 3/4" thick 8' long 3' deep premium solid birch hard ply on top of the supports. WOULD I GET SAG IN THE MIDDLE ???   Mind you the sawhorses will be placed 18" in from the edges.

Any input would be appreciated. I'm creating a new work top to give my place more structure and evenflow.  The offset tables are driving me batty