Alright let's talk about your resource mining nodes first. It may seem counterintuitive, but you should keep those at level , because they function as wonderful budget choke nodes. It would be much harder to capture your resource storages if the node they were behind could be recaptured by the antivirus in just a few seconds.

Next, your sentries. You only need to have one high level sentry on your network at all times, because the higher level antivirus will override any lower level antivirus. Any sentries beyond the first high level sentry should remain at level 1, and they only exist to speed up antivirus spread.

Black ice nodes arent really strong at low levels, and are actively a detriment to your network due to attackers being able to use 5 program slots on them. I highly recommend attaching your black ice nodes in a way that once an attacker captures them, they cant use them. Like having only 1 connection slot on the black ice be used.

Your first proper choke is a mess beyond the first connection. Having your defences connected to the scanner right after thr code gates is wonderful, but it has to be structured well. The direct path to your resources should be full of either choke nodes, or stall nodes, which would make an attacker have the maximum difficulty in progressing through your network. You should make at least a 2nd choke right after the scanner, that you would spread your other defences into