Four-strokes can (in theory) get away with less oil than 2-strokes -- mainly because the oil tends to pool in the crankcase so a lower oil content just means it takes longer for that pool to form and it will be smaller.

Two-strokes however, are a totally different kettle of fish.

The only lube available to the 2-stroke is the oil that's mixed with the methanol. There's no "raw oil" in the crankcase of a 2-stroke so it really needs a highler oil percentage (because it's so diluted by the methanol/nitro) if you're to avoid excessive and premature wear.

Despite this, I run my 4-strokes and 2-strokes with at least 20% oil (by volume). An extra few percent of oil is much cheaper than new bearings a new conrod and/or new piston ring/liner and it offers insurance against the engine going slightly lean due to atmospheric conditions, dirt in the line or whatever.