  Turbulent motions in the circumgalactic medium (CGM) play a critical role in
regulating the evolution of galaxies, yet their detailed characterization
remains elusive. Using two-dimensional velocity maps constructed from
spatially-extended [OII] and [OIII] emission, Chen et al. (2023b) measured the
velocity structure functions (VSFs) of four quasar nebulae at
$z\approx\!0.5$--1.1. One of these exhibits a spectacular Kolmogorov relation.
Here we carry out an ensemble study using an expanded sample incorporating four
new nebulae from three additional QSO fields. The VSFs measured for all eight
nebulae are best explained by subsonic turbulence revealed by the line-emitting
gas, which in turn strongly suggests that the cool gas ($T\!\sim\!10^4$ K) is
dynamically coupled to the hot ambient medium. Previous work demonstrates that
the largest nebulae in our sample reside in group environments with clear signs
of tidal interactions, suggesting that environmental effects are vital in
seeding and enhancing turbulence within the gaseous halos, ultimately promoting
the formation of the extended nebulae. No discernible differences are observed
in the VSF properties between radio-loud and radio-quiet QSO fields. We
estimate the turbulent heating rate per unit volume, $Q_{\rm turb}$, in the QSO
nebulae to be $\sim 10^{-26}$--$10^{-22}$ erg cm$^{-3}$ s$^{-1}$ for the cool
phase and $\sim 10^{-28}$--$10^{-25}$ erg cm$^{-3}$ s$^{-1}$ for the hot phase.
This range aligns with measurements in the intracluster medium and star-forming
molecular clouds but is $\sim10^3$ times higher than the $Q_{\rm turb}$
observed inside cool gas clumps on scales $\lesssim1$ kpc using absorption-line
techniques. We discuss the prospect of bridging the gap between emission and
absorption studies by pushing the emission-based VSF measurements to below
$\approx\!10$ kpc.
