The Large Magellanic Cloud should be a wreck. It has spent gigayears in mutual tides with the Small Magellanic Cloud, exchanging gas and stars vigorously enough to build the Magellanic Bridge and Stream, and it is now plunging through the Milky Way's halo at high velocity on a likely first-infall orbit (van der Marel 2004; Patel et al. 2020). Yet its disk remains massive, rotationally supported, only moderately warped, dynamically cold, gas-rich, and decorated with a coherent spiral arm.
In ΛCDM the survival is hard-won. Close passages in a dense dark matter environment heat disks; dynamical friction between the LMC's own massive halo and the Milky Way's transfers orbital energy into internal disturbance; and simulations of comparable interactions routinely destroy long-lived spiral structure and produce warps far more severe than observed (Besla et al. 2012; Garavito-Camargo et al. 2019). Keeping the disk this intact through this history requires tuned halo masses, orbital geometries, and feedback prescriptions, and the tuning must coexist with the same halos' obligations elsewhere, to the Stream, the Bridge, the wake the LMC should raise in the Milky Way's halo, and the satellite-plane perturbation arguments.
The standing connects the LMC to the broader pattern of structures surviving their predicted destruction: thin disks through merger schedules, bars staying fast, and now a dwarf disk staying cold through an interaction history that should have shredded it.