About ARM or FPGA?

I think your tutor is right. The essence of ARM is to build various on-chip systems with ARM as the core. This requires solid Regester-Transfer-Level skills. In this respect, ARM and FPGA are parallel.

I don't know what the purpose of your study is. But if it's for employment, then I suggest you focus on ARM first, and FPGA can keep up. As you said, there are many ARM in China and few FPGA abroad. Moreover, due to the cost of FPGA, it will not be too popular in the future for a long time, and it will not be used in mass-produced consumer electronic products.

If you have any questions, you should communicate with your tutor how to allocate time and energy.