Need help with w/b vehicles deck

[forsakenirvy]

I'm trying to play w/b vehicles (just because I have mostly dominaria cards (I play about two months) and this deck is almost completely from dominaria and I don't want to buy expensive cards, which will be rotated soon). But full version is too expensive.

For now, I have two versions:
- Token-based: https://www.mtggoldfish.com/deck/1146265#paper
- Midrange version: https://www.mtggoldfish.com/deck/1146013#paper
- Knights: https://www.mtggoldfish.com/deck/1147681#paper

Which one is better? (meta is a lot of r/b aggro, monored, uw control, and a couple of g/b constrictor decks)

Any problems with my decks? What would you change?
Could you suggest me the better replacements from xln/rix/dom or something very budget? (I've written my replacements in description)

Which cards are important and which aren't? I mean, which cards should I drop to add cards from sideboard (I'm still thinking about it)?

[Mnemosyne]

I'm trying to play w/b vehicles (just because I have mostly dominaria cards (I play about two months) and this deck is almost completely from dominaria and I don't want to buy expensive cards, which will be rotated soon). But full version is too expensive.

For now, I have two versions:
- Token-based: https://www.mtggoldfish.com/deck/1146265#paper
- Midrange version: https://www.mtggoldfish.com/deck/1146013#paper
- Knights: https://www.mtggoldfish.com/deck/1147681#paper

Which one is better? (meta is a lot of r/b aggro, monored, uw control, and a couple of g/b constrictor decks)

Any problems with my decks? What would you change?
Could you suggest me the better replacements from xln/rix/dom or something very budget? (I've written my replacements in description)

Which cards are important and which aren't? I mean, which cards should I drop to add cards from sideboard (I'm still thinking about it)?

I would say that vehicles are a little redundant. As you have said, they are rotating out soon.
The best vehicles are in Kaladesh, and it is unlikely that they will get a reprint any time soon. Unless you already have Heart of Kiran, Skysovereign Consul Flagship or Aethersphere Harvester, I wouldn't bother getting them. They will rotate in October.

That being said each are more or less under $2/3 dollars.

I would suggest that you do not try to modify tier one decks with budget alternatives, just because the net deck versions are meta tailored to the pro-tour, unless your LGS is using the same meta? The alternatives would also not work effectively, as the decks themselves are designed to be efficient for the archetype.

Gideon of the Trials, for example, works in concert with Heart of Kiran, as you can remove his loyalty to pay for Heart of Kiran's crew cost, and animate him as a 4/4 to crew Heart of Kiran, if necessary. Gideon also creates an emblem to make dealing with Gideon more of a threat.
Shalai, Voice of Plenty does not bring the same effect to your strategy, you wouldn't use a creature with evasion to crew a vehicle with flying, nor does it protect your Toolcraft Exemplar from Goblin Chainwhirler's ETB effect as it does not target you/or your creatures.

The same applies to Karn, Scion of Urza, except you are trading his ability to generate cards and artefacts that work with the deck's premise for a card that doesn't. Twilight Prophet, and Bontu the Glorified do not do this.

You might want to scrap this idea and instead build a deck that still is White/Black, but uses the cards you have.
(I am not saying that you are wrong in pursuing this idea, but it is more helpful for you, to instead do this. It seems like you are desperate to find a way to beat the top tier meta - Rakdos Aggro)

You have good cards;
(Vraska's Contempt, Seal Away, Cast Down, Shalai, Voice of Plenty, Lyra Dawnbringer) - Make a deck that uses knights - Knight of Malice/ Knight of Grace. Try to think of how the cards interact with one another. At the minute, I think that is your biggest concern in making a deck.

I would also advise you to make your decks here, as we don't have to use external links to see them.

I hope this helps, more than deflates you!