Yes and no. There's absolutely no guarantee that 2 sticks from 2 different kits will work. Ram is made of silicon. Most times, the silicon from the same batch is compatible between 2 sticks, which is tested by the factory before shipping as 1 kit. By using different batches of silicon, there's been no testing, so it's absolutely unknown if they will work together.
Meaning it does not matter if they are identical in every way, or totally not identical at all, it's all dependent on if the silicon is compatible.
Mixing ram is pot-luck, pure and simple