Question: Will I get good results if I switch programs and/or combine a few together?
Answer: No. There, done.
Now if you want to know why.... (this is actually quite important, so please feel free to read until the end)
Have you ever tried to bake a cake using two or three different recipes and used the various measurements from each? No, right? Because that would make no sense. Using the amount of sugar from one recipe and the flour from another might give you the wrong proportions to make a proper cake. You would get an end product that might resemble a cake, but it wouldn't taste as good as if you just stuck to one recipe the whole time.
Same thing with training programs. Each program should have a specific purpose to what it is trying to achieve for you physically. For example, some programs are meant to help you get stronger, some bigger, and some just to make you tired (these ones I don't recommend). If you try and mix and match programs (like recipes), you won't end up with as good a product (physical abilities) as if you just stuck to one program and worked at it until the end.
My point is, don't try and combine programs together or jump from one to another based on how you feel that day (Chest Day again?!). Personally, the programs I write for my athletes (and hopefully your S&C Coach as well) all have a purpose- to make strong, durable athletes that can withstand the demands of their sport and perform optimally all season long. If you start adding in an Instagram model's "8 Minute Abs" or a Pro Athlete's "Secret to Speed" work, it will throw off the recipe and give less than optimal results.
This goes for In-season work as well. I know some of you like to do your own thing when you go to the gym. While you might not think this matters that much, as long as you are working out, I want you to think of that extra work like adding extra sugar to a cake recipe. While coaches do put sugar (curls, bench, whatever your favorite exercise is) in to make the cake, it is in specific amounts for a reason- to get the best end product/cake we can. If you start throwing in tons of extra "sugar" because you like "sugar", then it will mess with the rest of the cake recipe. Now, if you really like sugar and want to add more to the recipe, it is best to check with the chef to see if that is okay. If you tell the chef what you want, they are able to help you change the recipe to still get a delicious cake without compromising the cake flavor.
Translation: Let your coach know what your goals are and they can help you with some added work if necessary to make sure it still fits within the program. Doing your own thing can mess with the outcome of the program and lead to less than optimal results (real-life example below).
So, be disciplined in your training for best results, communicate your goals with your coach, and you will end up with a delicious "cake" that can withstand anything sports throws at it!