Are some songs, despite beatmatch and keymatch just impossible to mix?

So I'm a total beginner DJ and I use the DDJ-FLX4 and I like to be what people call like a top 40 DJ or a wedding DJ or an open format DJ. I just want to play music and don't want to spend hours and hours pre-planning the whole set. I mean might as well just play that set and then bring a USB and just play that the whole night and leave halfway, right? So I'm trying to mix the song We Are One from Pitbull and S&M from Rihanna. They are both at 128 BPM and they are with the key 4B and 4A and I just can't match them. No matter what I do, I know I'm a beginner and all that but I just can't match them. I can try the high pass filter or the echo out that works for pretty much any song but I want a smooth transition between songs. I also don't want to just outro-intro every song the whole night. How do you go about that or do these songs just not match?