It's going to be a massive struggle, mainly because the low amount of RAM. If you were able to get 8GB in the system it'd be enough for a good experience despite the CPU being a little weaker... The RX 460 4GB is perfectly fine to run PUBG at 1080p around Medium settings at a good frame rate, the A8-7500 should also be able to keep it smooth enough especially as the game gets more performance patches and optimisation over time which has been improving. But again, the 4GB of RAM will make the system struggle as the game can comfortably use up to 6+GB itself (then you need to take into the account the 1-2GB you likely use in the background for OS and apps), but 8GB would certainly make it a comfortable experience. Hope this helps!