The lalafell clipping issues is just a product of their overall design. Pretty much you have a character model which is physically wider at the hips than shoulders in a substantial way. To get the "full range of motion" youd need on Lalas to hold weapons and do emotes, clipping will naturally occur. The issue would be rectified by actually broadening the shoulders a little bit, but in doing so, you square up their figure (to they become tiny bricks instead of potatoes). For female models, this would look even worse. This would then be resolved by applying human proportions to the Lalas, which would then change the design aesthetics. I did a quick bit of photoshop garbage to illustrate my point.
if the link dont work:
https://imgur.com/lkPxnla
Broadly speaking, when looking at the Lala model (F in this Case) on the left, the shoulders are to narrow. Thats why the Arms kind of lay away from the body like they do. This results in clipping though, when you think about it, because teh arms cant get a full range of motion naturally. Broadening the shoulders [2] helps resolve that problem and would help take care of clipping issues, but now you have a brick instead of a potato and it looks a little odd for female models. On Males, this wouldnt be as big an issue. This can be corrected aesthetically by adding in a bit of more humanesqe proportions (narrowing the waist and slight adjustments to hips as an example)[3]. But by this point, if youre gonna start editing the feel and anatomy of lalas, you might as well do everything and redefine legs, arms, and etc [4].
This kind of thing is easy to photoshop, but actually going in and tweaking an established model is a lot more work. You have to make sure everything that goes on that model still 'works'. This means adjusting armors, animations, rigs, and etc, just to make minor changes. Dont get me wrong. I would love models to be updated and fixed, but when they say its a lot of work, theyre not BSing us. It really is. If they decide to redo the character editor, then I would expect changes like this, but if thats not on the table, then we might just have to kind of suck it up and accept it.