Jayseas that question depends entirely and simply upon how much if any dihedral (upward tilt of the wings from the center section, and/or outboard panels as well as simple angled tip plates.

For example if the wings are close to flat the elevator and rudder only cannot work. In this case only elevator and ailerons will be effective .

Now if sufficient dihedral is used then elevator and rudder only can be quite effective and a useful method. In fact with an elevator and rudder only airplane increasing the dihedral increases the control response of the airplane and this is quite the opposite of the case with an elevator and aileron only airplane where flattening the wing increases control response.

Jayseas this is the most direct answer to you question possible. So for "eez of flying" only you know based on the lack of info on your design. Its because of persnikety design effects like I just described above that I am always preaching when you are new and learning to fly whether it be elevator and rudder, elevator ailerons or full house three axis and power designing your own first airplanes a really bad idea

John