If I were you and training for strength, I would squat every workout and deadlift every other workout just like starting strength recommends. Your deadlift will probably eventually get stronger than your squat especially when get to a point where you can only add 5lb per workout on the squat but can still add 10 lb per workout on the deadlift.
What is keeping your deadlift from going up? You mentioned your arm, is it your grip strength? Are you using a mixed grip?
If you are squatting every workout, only heavy set is needed to keep the deadlift progressing. Shit dude, you do it 2 times a week. When you are not deadlifting, you will be powercleaning for multiple sets which will also help your deadlift improve since the first half of a clean is a deadlift. If you do too much volume on deadlifts, you will not be able to recover enough between workouts and your squat will likely suffer.
You can try your program if you want, do whatever. Just know that coach Mark Rippetoe has already thought of all this stuff and that's why he made Starting Strength.