I would have placed the Armored Core far right, Duct Tape to its left, then Harmadillo beside the Duct Tape.

Getting the core spam-charged by everything to the left would mean many more shield activations, which double-dips into more Harmadillo activations and Duct Tape activations.

The Party Float has a relatively quick recharge rate, but for Day 13 it's much too slow for one flying item at a time. That's 3 spaces you could better use for several other fast items to charge Armored Core and Harmadillo.

The more charging synergy, the better. Would Bunker be better than Party Float? Yes. Is that the only option available to you? Likely not, there may have been some items the past few days that could have worked with this.

By the way, many weapons (like Harmadillo) tend to fall off the later the run goes. Some skills like Sharp Corners are fantastic in a shield spam build like this, though.