Just visible at the front of this image is a GCZ110 assault breacher vehicle that seems to be based on the Chinese Type 96 MBT. It's new to me but has probably been around for a while. I'm not yet clear on how engineering assets are organised within the PLA. 
There is an operational support and combat services support battalion within each brigade and an engineering brigade within each group army. The breachers could be task organised from either of these formations to support armoured operations.
What is clear is that almost every formation - including the PLA Marine Corps - has some form of assault breacher based on one of its organic vehicles. The exact reasoning behind this is unclear, but we can make an assessment based on some Rand research.
In 2018 the think-tank wrote that the PLA builds systems with which to confront opposing systems. So, a US air attack would be countered by an anti-air raid system. A blockade of Taiwan conducted by a firepower system, anti-air raid, and others. It combines units to achieve ends.
It is possible that there is an "assault system" or "breaching system" whereby a unit is set to breach an enemy's defences during an attack. This is just conjecture, but it gives an idea of how these elements might be organised, and why there are so many of them.
