2-3 Katsushika Suppression 2

The main challenge is a priority conflict. The enemy SGs have high ACC so you don't want to send evasion tanks, but the enemy AMR has high ATK so you don't want to send mitigation tanks. Since the AMR has such incredibly high ATK, this is a difficult stage to brute force.

Our recommendation is to use a mitigation tank (SG) that has the strategy Frontal Attack and an evasion tank (HG/SMG) that has the strategy Accompany the Close-Range. The SG will engage the enemy SG and stay between it and your evasion tanks. Meanwhile, the enemy SRs will move forward to attack your HG/SMG as they prioritize targets with low HP. In this way, your SG won't take as many AMR shots and your HG/SMG is far less likely to be shredded by the enemy SG.

Any SG at lvl 5+ will do as that's when they learn Frontal Attack. Any HG with their first Special Training strategy unlocked will do as that strategy will always be Accompany the Close-Range

ARs will do well here as they have high MOV and can chase down the enemy AMR quickly. An LMG may help kill the SG and LMG more quickly if they clump, but there's no guarantee they will.

These units will be essential to punching through the enemy frontline before the enemy AMR gets a lucky shot off.
Allied SRs/AMRs should have no issue hitting such low ACC units and will make the enemy's high DEF less of an issue.