I am sure you know that we are looking at renders here. Looking at my /dev/tty keys here and in hand, they are much lighter that these renders. Seriously, why worry? Mix and match, right. As they say here, make it your own. ;)
As @sdjones pointed out, the right Fn will either be in the wrong row or you could use the Sys key in its place. Aside from that, it looks like you should be covered.
The renders don't seem to show the row sculpting at all, but the actual photos (first 12 images, including the one below) show the accurate sculpting. This set does use R5 for the bottom row, unlike many other MT3 sets out there as you point out. So in this case the Fn key would be a different profile from the rest of the bottom row caps.
Can we please get better renders? Colors on renders are constantly off. They're desaturated compared to what it turns out to be in real life. (based on recent renders for lotr series)
The MT3 9009 PBT renders are reasonably accurate to what the set looks like in real life per my spectrophotometric reports and calibrated monitor settings.