MTH also make unit with fixed pilots that can run on 2 and 3 rail I have a number of them and love them.
I own MTH ES44AC with scale wheels too.
But I had to preorder them before the deadlines as it seemed like MTH was likely to cancel the scale wheel versions due to lack of preorders.
Even though these ES44AC were Proto-Scale 3-2 conversion capable and despite MTH’s 3-rail models being easier to locate, I learnt from these forums that MTH does not sell their fixed pilots for aftermarket 2-rail conversion.
Many years ago, someone on these forums compared MTH and Lionel’s versions of the Norfolk Southern heritage locomotives and Lionel seemed to have better road specific details for Norfolk Southern models only.
Also the Lionel diecast versions seemed to get positive reviews on these forums.
For these reasons I considered Lionel’s versions for 2-rail conversion.
These are just my opinion,