RE: processor speeds: well again, you have to compare specific models and apps. For Photoshop, a lot of the new 8th gen i7 processors may actually run slower. The basic trend is that they've taken previous 7th gen dual core processors and dropped the base clock speed (to reduce power consumption). To try to claim better performance, Intel is referring to making more of the 8th gen processors quad core (which Photoshop favors higher clock speed over cores). So I'd say the difference in 8th gen laptop processors isn't so much speed, but battery consumption. That benchmark site I previously linked is pretty good about just comparing processors alone: but the caveat is that applications are written differently and take advantage of different features of the processor (or GPU).
IMO, a touchscreen is pretty important for a 2-in-1. I've got a Wacom stylus that I can use directly on my Lenovo screen and supports pressure sensitive brushes in Photoshop/LR. You can try comparing the 8th gen i7 with the 7th gen i7 at that benchmark site. My Lenovo is a 15", which at the time 8th gen processors were just coming out. I sided with the Lenovo over other brands because it had a i7 quad core with higher clock speed (so it was better for me, who apart from PS also does video encoding and 3D rendering). Compared to what I'm used to (I have an older Dell mobile workstation that has no battery life now), its processor performance and *enough* battery life for my needs, makes it a good travel laptop for me.