Twist is just a troll on this site, calling everyone out whenever he feels like it. He's just mad that we gave him quality advice and it wasn't what he wanted to hear. Plus, he's also mad that we were upset at him for posting at least 8-9 topics on his Modern Marvel, which were all the same. Then, he was mad that I called him out for lying about his experience when he said he has bowled for years yet he posted that he was new to the sport. To answer your question Rightycomplex, twist has no facts to make an uneducated response to good advice. Especially from charlest, who is one of the most respected members on this site and has helped many, including myself. He just stirs up trouble ever since he started posting on here about a week ago.
Anyways, back to quality advice. What I would say is that if the 5 balls fill a gap or provide a reaction in the arsenal that you don't have or have been missing for a lane condition, then it was a good purchase. Originally it was questioned if you did research, which you clearly state you did.
The only spot I can see some potential overlap would be with the Theory and C-System 3.5 as both are good on heavy oil. This is where using different layouts will make the difference. What I would do in this case is possibly drill the Theory pin down to give it an earlier read in heavier oil due to the slightly stronger cover. Then, I would go pin up with the 3.5 to give yourself additional length but have the motion be primarily on the back.