Discussions, often spirited ones, come up all the time about ‘proper’ scale, vs ‘toys’. Nothing is ever solved because everyone is right, and everyone is wrong. It just depends on the frame of reference of whomever you are talking to. Whether some folks like it or not, LGB was THE standard in large scale for decades. They carefully chose their target audience - those folks who wanted robust, good running, good looking trains for indoor and outdoor use. And who were willing to pay for superior quality. - and then Lehmann produced exactly what those folks wanted. If you preferred perfect scale, or cheap and cheerful they never claimed to be what you wanted. - Yet some folks slammed them for not being exactly that. Bachmann and Aristo have, for better or worse, chosen the target audience of those who seem to prefer lower price and more scale fidelity over quality and durability. As with LGB, it’s not ‘wrong’, it’s just a different target audience.
What has this to do with you and me? We need to take the same approach. When you plan projects, you need to decide WHO the target audience is. If you are building for a club or other train folks you will need a different mindset and standard of finish than if you’re building for family and friends. Trust me, your kids won’t disown you if something is off by 3 scale inches or even a couple scale feet. MOST of your train buddies won’t actually embarrass you over it either (unless you REALLY make a hash of it… but those that do probably deserve to be shown the door anyway.) While a Colorado NG enthusiast might be really impressed if you build a historically accurate model of D&RGW #483 as she appeared on the afternoon of August 26, 1943 at 3:52PM… your 4 YO grandson will just be mad because you say he can’t touch it.
Route 1: If you want to mostly run in public, then you should plan for durable, easy to repair, and reasonably good looking. Most folks can’t tell a Baldwin from an Alco or Aster from New Bright, and really don’t much care, either. Kids (and many adults) WILL try to touch your stuff - Easier to plan for it than to get upset after. Thomas WILL get more attention than your scale models. Folks will mostly just ask how much it cost because they are curious, or maybe because they think you’re a bit daft. - not why you put an incorrect paint scheme on something XRR never owned.
Route 2: If you want to win a contest or get printed up in a magazine, then by all means go whole hog. Put a perfect scale pickle chip on a perfect scale sandwich in a perfect scale lunchbox in the perfect scale toolbox. If you just plan to sit it on a shelf to look at, then you probably will want to draw a line someplace short of that. If you plan to actually RUN it, then realize that some of the more fiddly bits are probably not going to hold up for very long.
Route 3: For ‘general service’ if all the parts look like they belong together, and the model works visually with everything else on your layout, then it IS ‘right’, even if it is wrong. When you take in the whole picture, you won’t really notice that the gauge is off by 6" or the building has 4 windows instead of 5. And stuff that looked like total crap from 3" with a flash often will look great from 3 feet away under natural light. But a perfect scale model that overwhelms everything else around it may totally ruin the mood you are trying to set. OTOH, painting an undersized cow to look like a pig might not be very convincing when viewed up close.
What I’m trying to say is, whimsey, selective compression (aka rubber ruler), impression rather than fidelity, even rigidly counting rivets ALL have their place in a properly equipped toolbox. Knowing when and how to use them is what separates the fantastic from the merely good. It’s an art, not a science, but it can be learned. And choosing your audience and playing towards what they want and expect is the first step.