The real issue I have with a-train in this context is the fact that Casino asked for a 3rd for squigly/filia. Squigly can get away with having A-train because with charge and meter her neutral is pretty solid. Filia without a horizontal pressure assist vs someone with any neutral assist is a very hard battle. I mentioned earlier that my recommended order for the big band team would be filia/squigly/band; if instead of filia you had a character like double/bella (these are just the characters I see sage do this with w/excellabella) who could navigate the neutral game mostly on their own or could make better use of a squigly assist like drag-n-bite for the neutral game than filia could, then you could have BB on anchor with the a-train as your setup/combo assist for the team. A-train doesn't give filia what she needs however.
I find it strange that you feel that way.
I can see you saying that for filias neutral to a certain extent. But most filia players neutrals are just lacking. They don't use half of what filias got in order to move around. Pikmario is one of the few filia players I see using her mobility in what I would call the "correct" way. Airballs to move around mixed in with superjump and air dashes and ground runs. It's hard to stop a filia from getting in when she's using all these options.
Now think about how hard it would be with a limited ability to jump... You really keeping filia out well then?
Squigly, parasoul, double, BB are the only characters I can really see able to put up a competent ground based keepaway defense without jumping IMO. Peacock with lower ability to jump is screwed cause she can't airdash or access jhp and jhk for keepaway, and filia has always done well against her anyways. Pw would be a tad bit screwed with limited ability to fly around... Etc etc.
Also, chicken blocking filias ground based offense is one of the primary defenses against her. And on point she doesn't really have any safe ways to deal with that directly. She can airthrow, or she can go low into a series of choices that are all punishable on block. So having something that grabs jumping characters and allows filia to easily push her high/throw game on the opponent... Could be very good if used intelligently.
But I digress. I'm not making the move out to be some uber stellar thing. I'm just saying that SG as a community may not have either the experience or the skill to use the assist properly at this time.
Using the assist properly goes like this:
Knowing what it can do for your character at neutral and how to restrict your opponents air options.
Knowing how to take advantage of your opponent no longer using air as a first option in their gameplan.
Knowing how to use the assist in your resets to enforce ground based respect or to even learn how to use it to crossup aerial foes in air based resets.
Knowing what matchups/playstyles it is very useful in and what matchups it isn't super useful in (hint, it's highly useful against painwheel, and any opponent that loves to rely on air based offense)
...
A lot of times it's less about what something does and more about your knowledge of what it does and planning how to make that an important part of your gameplay, and then having the ability to execute your plan.
Sure, the tactic can actually degrade your teams strength depending on the tactic employed. But only through actual play testing can we see the true strength of something, and then, only if we actually know what we are doing in the first place.