If your needs are being taken care of between the Eloquencer and PNW, there's no reason to expand into a dedicated LFO and clock modules. However, you are eating up outputs that can go towards other functions.
The Eloquencer and PNW may or may not be able to modulate their own LFOs and clocks... or at least not as well as a dedicated module. It all comes down to usage. So take everything with a grain of salt.
As far as the 2HP VCO. It has a features in it. But take a look at an Intellijel Dixie II+. You get more waveforms, a sub output, attenuators, you can select the octave playback, linear and exponential FM modulation (plus a secondary FM source), you can shift the VCO into LFO territory.
The 2HP VCO is $129. The Dixie II+ is $229. 2HP vs 8HP. But if you're going to put another VCO into your system, I'd go with the Dixie as you'll get more out of it. You could go with another VCO... but the 2HP is lacking features that are important in my opinion.
Rather than the 2HP MMF, look at the Steady State Fate MMF. There's a $50 difference. But you also get 1V/Oct tracking, plus FM and a PING input. You'll get more use out of the Steady State Fate.
There's no problem with the Mutable Instruments stuff. But I've found having traditional envelope generators onboard to be a worthwhile investment over modules that require a lot of button pressing and memorization of modes and features.
Again, all with a grain of salt.