No. It's not. It's a matter of what fictional facts we've established. If I tell the DM, "I move to within 50' if the goblin."
That is a tactical move, and now a fictional fact. The DM can't suddenly change that.
That gives specifics on positioning with respect to the goblin. But then it's left to DM fiat where your positioning is relative to the slime.
If you can track every relative positioning, between every creature, and every possible terrain feature of interest, then yes, ToM is effectively equivalent to grids, with respect to mechanics like forced movement. But unless you're some kind of savant that can play 10 simultaneous games of blindfold chess, that isn't possible.
Again. Wrong. It's up to, "Did you describe yourself getting in position to push the goblin into the acid slime? Yes? Ok you do if you hit. No? Then describe how you set that up."
How does one "get into position" with respect to the goblin, that somehow changes whether the goblin is 10' or 15' away from the slime? This line of questions does not make sense in the example I responded to.
I wouldn't enjoy that either... That's why we roleplay it out.
"Ok, you see the goblin coming down the hallway."
"How far is he?"
"About 60', just at the edge of the dimness of your torchlight. He sees you and starts reaching for his club."
"Great. My movement is 20', but if I charge I can move 60'. Is there anything that might hamper my movement in the hallway? Like, rough terrain or something?"
"Nope. Just a dungeon corridor with flagstones for flooring."
"Great. I charge."
I mean, where in that is the DM fiat? Nowhere. It's the player's prerogative to use questions to clarify the environment.
There's none in that example. That is a different, far simpler, example than the post I replied to. The problem arises from complexity. Sure, the first round you can track how far the combatants start from each other. But 3 rounds later? You really know, with certainty and without handwaving from the DM, the distances between every combatant, and every terrain hazard? I doubt it. Your original line of questions suggested that the player did not know, until he asked the DM, what distance the Goblin was from the slime.
The same must occur with grids... "What's the wavy line you drew? It's red is that a wall of fire?" "Oh, no, that's just a curtain."
That's clearly not even remotely similar to DM fiat. Clarification is not fiat.
The DM's answers establish facts, that we can make decisions based upon.
Sure, if you're playing with a 5 year old, those facts might change randomly. But, we're like, adults right?
But even adults have a limited capacity to remember facts. Mentally tracking the exact relation of 10 different creatures to each other, and various terrain hazards, is well beyond most of us.
Also, I saw this article linked from RPG.net:
Grids Again | Lizard's Gaming and Geekery Site
It very effectively expresses much of my thought process on grids, vs. gridless.
I can traditional D&D TotM of the type you are discussing a particular implementation of TotM. Traditional D&D grid play is also a particular implementation. Or rather, each version has a had a particular implementation that favored one or the other. Your question to me is the same as, "Now that we've narrowed you down to cars and trucks, which will it be, a Toyota Corrola or a Ford Ranger, since those are your choices?"
I'm not seeing a meaningful difference between ToM play in any past edition of DnD. They were all basically the same. Everything was specified in absolute measurements (inches in original D&D, then later feet, then squares in 4E). There is a world of difference between that, and Burning Wheel's abstract distances.
It's an example of an agnostic mechanic, between grid and TotM. How precise or abstract you want to make it, and similar mechanics, is another question entirely. On that last part of your quote, I'm not sure you got the import of the example, though. The example is that you don't get so zoned into knocking people into things, that you leave out room for the possiblity that getting people away from you is useful. Find a way to model that in the game, and the problem of grid/TotM translation goes away. You can still knock people into things for even more fun when available, but it is no longer the main focus.
OK, but I just don't see those kinds of abstract mechanics being an option here. 5E is supposed to "feel" like traditional DnD. Especially the core. Abstract distance mechanics are extremely far removed from how DnD has traditionally worked.
Also, your push is only a pale shadow of what pushing is in 4E. Pushing someone away from you is rarely an especially useful thing. Basically, it only matters if you can't back up for some reason. Pushing things into specific places is the primary usefulness of pushing. Take that away, and almost nothing of value remains.
But it's only an example. Name me another place where grid/TotM doesn't translate back and forth very well, and I'll give you another one.
Opportunity Attacks for anything other than simple "I engaged him, and now he's moving away". For example, is the Fighter in the way of the monsters trying to reach the Wizard?
AoE effects. A simple Fireball is almost impossible to resolve without extensive DM fiat after a round of combatants mixing themselves up.