Despite the same brand (Kingston) and same speed (1600 Mhz), RAM size, timings and voltages are off.
Genesis is 2x 4GB while Savage is 1x 8GB.
Genesis operates at CL9-9-9-27 @ 1.65V while Savage operates at CL11-11-11-? @ 1.5V. Even if you enable the XMP for Savage to match the timings to CL9-9-9-? @ 1.5V, voltage is still off between the two RAMs (1.65V vs 1.5V).
Also, since there is no value for Row Active Time (tRAS) for Savage RAM, the Savage XMP profile timings (CL9-9-9-?) may not be same as it is for Genesis RAM (CL9-9-9-27).
Here, i'd say you'd have 50:50 change of Genesis working with Savage in the same PC, if even that much.
It's bad idea to mix RAMs since while mixed RAM can work in the same PC, most of the times, it won't. If you want to get 16GB of RAM, buy the set of 2x 8GB or 4x 4GB DDR3 RAM, where all RAM sticks in a set are guaranteed to work with each other by the RAM manufacturer. Hence why they are sold in a set and not individually.
While the RAM make (Kingston), speed (1600 Mhz), timings (CL9-9-9) and voltage (1.5V) is same between Genesis and Savage RAM, you'd still have 50:50 chance of them working together.
You see, when RAM DIMMs are made, they are tested with each other and those sticks that get along well are put into sets. First set to be made is the set of 8x RAM sticks and sold as 8x RAM sticks in a set. If the set of 8 doesn't work, it's divided into half which makes up two sets of 4. If the 4x RAM sticks do work together, the are sold as 4x RAM sticks in a set. But if the set of 4 doesn't work, it's again divided into half, making two sets of 2. Two RAM sticks that work well with each other are sold as 2x RAM sticks in a set. Those RAM sticks that doesn't want to work together at all are sold as single RAM sticks.
And because you already have a singe stick and you're planning to buy different model single stick as well, there's 0 guarantee that they work together. That's just how RAM mixing is. Though, DDR3 RAM is more forgiving in RAM mixing than DDR4 RAM is.
Long story short:
Does Savage RAM work with Genesis RAM? Maybe (50:50 chance).
Getting as same spec RAM as you already have does lower the risk of two sticks not working together but it doesn't remove the risk. Even when you get identical part number RAMs but where both were sold as single sticks, chances are still 50:50 at best.