No, I don't think that it is a lot. You could get away with every-other-day injections (EOD). All depends on preference and goals.
To answer the question ... you do know that you can pull both into the same syringe for a single 2ml injection, right? If you don't, let me tell you how to do this. From the start: clean your vial with an alcohol swab, then you will put your needle on the syringe, pull back 1ml of air, put the needle in the vial, inject that 1ml of air (to create a pressure in the vial that will help pulling out the viscous oil), pull out your 1ml, remove the needle from the vial.
Then, pull another 1ml of air into the syringe, and get a new needle. Now, get your second vial (wiped with an alcohol swab) and inject the second 1ml of air. Don't inject the 1ml of oil in the syringe. Now pull out your second 1ml of oil. Get a new needle. Inject the 2ml mix.
Now, if you are thinking about mixing the prop with the tren in, let's say a 20ml sterile vial ... I guess you could, but here are some things to think about. Make sure that the mixture is 1:1 or that the volume of prop is the same as tren (I assume it is and both are 10ml). Now here is why I have thought about this, but haven't done it (and I am going to speak a little geekish here).
When you mix the two, you would need perfect mixing to ensure that when you pull 2ml that you have exactly half prop and half tren. Statistically speaking, that isn't possible. It may turn out that of the 2ml 30% is prop and 70% is tren. Or whatever combination you can think of. This is the case with all mixtures.
There may be X amount of N substances in a mixture, but to say that you have exactly X amount of each substances in each and every injection is false. (This is unless it was all put into BA/BB solution at the same time.)
So, when you do the double vile, 2ml injection, you know exactly what you have in each and every injection.