Not sure I'm following all of this. How do you influence surprise by tactical choices, other than having a ranger in a party (which is really a personnel choice, or arguably a high level strategic choice)?
The same way squads have achieved surprise throughout history. Put out screeners; make contact without giving yourself away; manufacture contact to your advantage.
You have to accept a modicum of risk. Halflings and elves start out at level 1 with 4:6 surprise in light armor. They're perfect screeners. Have them out ahead of the main party. They might get hit with a trap or something, sure. You've got to take care of your screener with healing them up to full whenever they take any damage. (But even then - what's better for your healing reserves? That one or two characters get zapped by a trap or the whole party gets zapped?) By mid-levels invisibility is available; so is flight. They combine nicely. Infravision becomes available to human spellcasters as well (or possibly by magic item). Familiars may be able to give a heads up and not look out of place. An illusionist can change self and reconnoiter looking like one of them - they don't have to go all through the enemy location and subject themselves to close inspection, just get the gist from nearby without looking immediately suspicious. There's a ton of options - it really just comes down to what assets the party has available to it.
And (at least in 1E) if you surprise something that doesn't necessarily mean
they saw you. Anything with surprise can always choose to retreat without much risk whether seen or unseen. The screener is also at max movement; most stuff is moving slower, or at best tied. So the risk of getting run down is low; they're either unseen or have a good head start. And if they are seen (DM judgement) they're leading someone who thinks they're chasing weakness right back into the teeth of the party.
So let's say that they aren't seen - they make contact, observe for a few seconds to get the gist, and slip away like a good guerrilla fighter does without anyone the wiser - the party has a ton of options now for how to manufacture surprise. Invisibility, subterfuge, illusion; In low-light environments hide the majority of the party behind a darkness screen you cast on a rock tied to a string you pitch ahead of you as you go, using this and silence to mask your advance on a known enemy in a known place while your screener goes out in front of those driving "blind" just to make sure the way is as expected. - the list goes on.
Prepared ground is another way to manufacture surprise. If the party makes a nice little nest of hidden equipment somewhere, they can lead attackers back to it where they have camouflaged stakes, ditches, loaded crossbows, etc., waiting. The classic ambush. Even if only a portion of the enemy followed them, its defeating in detail. (and eventually that enemy is going to send out a 2nd patrol or come out in force when no one comes back) Etc., etc., etc.
D&D came from a minis wargame. That war game is still at the heart of the engine. Use it to the fullest.
I know a lot of players would rather everyone blunder around as a group because they dislike stretches of game where some other player is in the spotlight for long periods of time, or no one wants to take what they see as risk instead of reward. And that's fine too. When DMing, I don't care if players want to give up advantages because of such concerns. When I'm playing, we're all sitting around the same table so I don't particularly care if what I'm hearing the DM say is because my character is seeing it or another character is seeing it. I'm here to explore, kick butt, and get rich so I have the resources to create more as a player. Whatever tilts the field in my direction so I can do more of that, longer, in the least risk possible is my objective.
I get how spell choice can affect attack order, but I'm not sure I get what you are saying about deployment of high dex characters. Are you saying that you tend to give them a missile fire role, and put low dex heavy armor types on the front line? If so, does that mean you tend to lose control over where the front line is (if the other side gets to move its front line into position first)?
If I have tactical input into my party I'll always suggest high-dex characters shooting whenever it makes sense to do so, which is often. Only for missile attacks does your dexterity reaction bonus reduce your initiative. So if you have a 17 dex character and they're shooting with their bow/sling/whatever, they always go 2 segments earlier than they would have if they didn't have a high dexterity. Basically, they have the benefit of the best possible initiative outcome 50% of the time, and segment 4
at worst. When you're trying to disrupt enemy spellcasters no one else on your side has closed to melee with before they can launch a stinking cloud or whatever, this is very beneficial. If your missilers are always able to attack as they choose from the very start of the round, and spellcasters are always finishing spells at a delay of X segments of casting time...
Or they can pick off heavily wounded enemies and finish them before they get in a strike; or if they're fleeing without someone able to cut them down the archer can hit them before they get around the corner. Say the rest of your party doesn't have init until segment 3, but the wounded bugbear will attack your wounded cleric on segment 2 - but your archer goes on segment 1...(there are times when shooting into melee is the best risk; I always want the option).
As for front line, encounter distance manages this much more than dex. I presume you're talking about surprise? High dex reaction to surprise is individual. And as mentioned in the other thread, I don't allow high dex characters to take their own action during surprise, only to drain away the surprise segments of those trying to strike them. Even if I did allow action - how many high dex characters are there? I don't want them establishing a farther partial front line of one or two PCs against 4-8 enemies; that's just those characters getting flanked at +2 to hit. Better to stay in formation.