Absolutely, a three car 170 is 69 metres long; a four car Pacer is around 60 metres.
I'll add a bit of my experience of the Harrogate line as these 170's have been introduced (and, presumably, Pacers and Sprinters re-purposed elsewhere) ... Mostly from the morning peaks into Leeds and evening peaks back again.
Before the timetable change, the line would just about cope, provided nothing was cancelled or short-formed. In the peaks, trains are every 10-20 mins. Most trains would gradually become 2-3 mins delayed over the Leeds-Harrogate section, but otherwise nothing spectacular. But a cancellation or short-form would just cascade problems ... one overcrowded train/platform would lead to over 10-15 minutes delay, pushing back into the next train, which was trundling along close behind but relatively empty.
The timetable change brought some 170's, which stabilised to 3 regular diagrams (2 Knaresborough, 1 York). The other trains were still a mish-mash, and still subject to both cancellations and short-forms. Delayed starts from either end, and waits outside Leeds meant the initial service ran regularly enough, but with varied delays. At Leeds, for some reason, people preferred to (over)crowd onto a 2-coach pacer rather than take the comfortable 170 with air-con that would follow 10 minutes later.
As we reached August, things stayed in this state.
September seems to have brought much more stability. There's a 4th 170 running now (though only on a diagram that runs in the peaks/evening), and it strikes me that there is much less short-forming on the line. Platform choices at Leeds have been sorted out, and trains quite regularly depart on time from Leeds or Harrogate. There's still a gradual decay on punctuality along the section inbetween, though. But the service feels pretty good now.