That's essentially how initiative works in Moldvay and Mentzer. it's simple, it's fast, and it's easy to explain.Just that? No "longer weapon gets first strike when closing to melee"? No "fighters with multiple attacks always strike first with their first attack"? No "when not closing to melee, on a tied initiative roll, lighter/shorter weapon strikes first"? Did you guys require casters to declare spellcasting before initiative was rolled?
I definitely remember most groups just rolling d6, side-based initiative like you describe. But how ties were treated or whether any of the exceptions were included varied a bit from table to table.
Understand that AD&D 2 was coming out knowing that it was in fact going to be competing with B/E/C; the master rules are about the same time as AD&D2 in release.... B/E/C/M is a different game with many overlapping mechanics - both deriving from Original Edition... So they didn't feel the need to "keep it simple" since Frank Mentzer had the simple side covered with the B/E/C boxed sets.Yeah. They did massive surveys on what fans wanted to see in 2E, but some of the design decisions I really shake my head at in retrospect.
Like going with 3d6x6 for ability scores, while retaining (somewhat cleaned up and slightly simplified) ability score charts which really require numbers of 15+ for bonuses in most cases. Which was just nuts. When Gary made the original version of those charts in the 1E PH, he stated that he expected PCs to have at least two scores of 15+, and when the DMG came out, the primary ability score generation method was 4d6 drop the lowest, arrange to taste.
Or the initiative system which made shorter, lighter weapons virtually always win initiative over longer ones with more reach. TBF, the 1E initiative system was FAMOUSLY confusing, bad, and overly complex with special sub-rules, and basically impossible to play as written. 2E's system was definitely much better and cleaner than the mess 1E had, but the core basic concepts in the 1E system were definitely more realistic (and to my mind, more fun as mechanics) and could have been simplified easily without switching entirely to the new system which had its own issues.
Or relegating gold for XP to optional rule status without giving any serious guidance on how to award xp for stuff other than killing monsters.
Too bad the retailers generally only understood the difference if they actually played, and most didn't. Hell, many players BITD didn't. I wasn't cognizant of it when I bought the (then brand spanking new) Basic Rulebook (Tom Moldvay's version). (It was available either as part of the $15 box, or as a $9 shrinkwrapped book. Due to allowance issues, I got the latter... )
As for the higher stats for modifiers?
OE had +1 at 16, and -1 at 6.
Sup 1 added some mods. That's Gygax's work.
AD&D 1E follows Gary's lead, as it was basically "Gary Gygax's D&D as of 1978"...
AD&D 2E follows AD&D 1E. So it's clearly a "Blame Gary" situation.
Holmes uses a different chart, and I don't have my books to hand. ISTR it being simplified from OE Sup 1&2..
Meanwhile, the simpler modifiers in Moldvay follow a smoother distribution... not quite as smooth as modern, but I prefer it...:
Frank Mentzer rewrites and slightly revises Moldvay's work, then expands it later, into a whole 36 level game (for human PCs; The demi-humans get essentially 16 to 18 levels, but HP only for 8-12 of them, via the Attack Ranks system.) But he keeps the same simple modifiers table. (I do wish he'd gone to d20's roll-high for thief abilities, and for general skills... but, nope...)
Aaron Alston and Troy Denning revised the Basic to Immortals line in the early 1990s... Troy doing the BBBB¹, with its cardstock paper figures and big battle mat, single volume rulebook aimed at levels 1-5, and a nifty adventure which uses the figs and battlemat. Aaron did the Cyclopedia, which covers levels 1-36, and adds an option for the demis to hit that level as well... He also did the Wrath of the Immortals big box, which revises Mentzer's Immortals rules, and adds a big campaign...
D&D 3E takes a cue from B/X, B/E/C/M/I, and BBBB/Cyclopedia on stat mods. 3E is really about dead center between the two in complexity. At least at first.
As for AD&D 2E Initiative? I've known groups who used it with all the bells and whistles, others who used individual initiative with WSF, others using individual without WSF, and others using side-by-side; those last two also exist in B/X and B/E/C/M/I... This also is part of the design calculus: by having the two be significantly different, but still largely interoperable, the adventures could sell across the gap, and groups could customize.
Unfortunately, customizing was becoming less and less common, in parallel with the rise of videogames. There's a paradigm shift in attitudes towards rules in wargaming in the 1980's, and it also permeated the RPG sphere. If there's one good thing the OGL has done, it's to make homebrewing legit. (There are others, but irrelevant to this issue.) Between the OGL and the OSR, mix-n-match and create your own variant attitudes are back. The best are great... most are, as Theodore Sturgeon's maxim² states, "Crap."
¹: Big Black Box Basic. By Troy Denning - a rework of Mentzer to go with Aaron Alston's rework of B/E/C/M/I into two components - the Cyclopedia including all of B/E/C/M, and Wrath of the Immortals, reworking entirely the Immortals ruleset.
²: Sturgeon notes, "90% of ëverything is crap.