All other factions have stock light AI vehicles to fight against CQC units in the early mid game. Soviets have stock flamethrowers, the M3 and Penals to ward off CQC units. OKW has Sturmpioneers and STG 44 Volks, Ostheer has stock flamethrowers and PGrens. USF has close to mid range orientated mainline infantry.
The UKF are the only ones who can consistently get overrun by CQC units (most notably on urban or other CQC orientated maps) because they have nothing in their stock arsenal to efficiently stop CQC units. The Universal Carrier can work, but doesn't on most CQC maps. The AEC doesn't deal enough AI damage.
Now since we can't magically conjure up a new AI vehicle, and since we do not want to buff Royal Engineers for obvious reasons, they will get the Assault Officer to help defend Infantry Sections from getting overrun by CQC units.
If the idea is to use the officer against Assault grenadier he probably comes too late. Other than that there not many Axis stock Axis CQB units out there to begin with.
UKF have problems but CBQ is not one imo (for instance grenades can work fine) and there a number option in solving some of their problem.
One could try to make:
Hammer/Anvil option available for infatry giving access to 5 entities/Bren modeled after BAR and 4 entities Vicker-K modeled after Grenadier.
For vehicles one could make make the same option available with AEC/Valentine making bofors stock
and/or
one could decrease the power level of Centaur making available earlier.
Or one could make Ro.E available earlier so that they can help defend vs CQB units.