▲仅就 many within the public sector 这搭配来说，many的词性应该是代词，因为它后接接了介词短语，这个介词短语应该是修饰它的定语，意思是：这个公共部门里面的许多……

▲类似的用法如(many均为代词)：

He chose a shirt from the many in his wardrobe. 他从衣柜里众多衬衫中选了一件。

This is a view echoed by many on the right of the party. 这是党内许多右翼分子都重复过的观点。

Many in the Anglican Church are still opposed to women priests.  英国圣公会中的许多人仍然抵制女祭司。

He lectured in such a way that many in the audience found him impossible to understand. 他这样讲课，听众中有许多人都觉得很难懂。

Children, many with their faces daubed with paint, ran among the vehicles. 孩子们在车辆中间跑来跑去，许多脸上都涂着油彩。