First off let me be the first to disagree

Most RPGs come before or in tandem with the miniatures game.
Star Wars - West End, D20/Saga D20..now followed up by E20 -all with variations of miniatures and RPG rules. Most of us have a hard time tracking what came before what.
Dungeons and Dragons -Long life of role-playing before the mini rules came out. Now they are intrinsic to the game
Iron Kingdoms - In tandem but released after the miniature rules became popular and used 3.5 D20 rules which were not anything like the mini version.
The mechanics from similar to completely different. While it may be nice to have similar systems it has never been critical to the success or failure of an RPG. It should parallel the game but a "seamless" integration should not necessarily be a goal.
The system must be solid and consistent
They system must be reflective of the game world but a bit more forgiving in the survival aspect. The PCs are the HEROS (or villains) The system could be pips, armor and damage reduction, wound levels or any number of the available mechanics out there.
They system must be supported by follow up releases. Just like minis, the releases must be frequent.
The system must provide crunch. This is especially true with SCI FI gamers. The players want to know what each and every piece of equipment does. They want to see the rules to create or modify their own weapons. They want to personalize their power armor. The role players want to know about history and units designation and lore. They want to see
unit patches, armor schematics and art to support all of it.
An RPG system must provide all of that.
The combat rules in LOS are simple and very straight forward, I don’t want to lose that. Especially in a RPG where most of the players are into the RPG part more than battles. (If they were more into battles they would be playing the miniature game more than a RPG.)In my 25+ years of GM/DMing I find that to be the exact opposite. The nature of most role play scenarios are based in conflict and most of the time that conflict is resolved by combat. There is, of course, always an individual or two who are hardcore RPer's and they must be catered to by the DM to maintain interest. These are typically the minority.
Most of the time its Steal That, Break Those, Capture This or Kill the Boss and get awesome loot scenarios
Almost every supplement of every game is a long series of fights, obstacles and puzzles mixed with some role playing
opportunities. I don't think I have ever seen a supplement that is marketed to "Guarantees long hours of talking"
Action is where its at and LOS provides a huge number of opportunities for that.