速度 and 歩幅: adjusted speed and a naturally changing stride
Compare bicycle and work speed with a companion-based stride adjustment and natural lengthening while hurrying.
速度: reduced speed and prioritized accuracy
速度 (そくど) means speed. 「坂道では自転車の速度を落とした。」 means “I reduced my bicycle's speed on the slope.” The bicycle's speed was reduced on a slope, without a numerical value.
「作業の速度よりも正確さを優先する。」 means “We prioritize accuracy over working speed.” This sentence prioritizes accuracy over working speed.
歩幅: matching a companion and natural change
歩幅 (ほはば) means stride or step length. 「同行者に合わせて歩幅を小さくした。」 means “I shortened my stride to match my companion.” The stride was shortened to match a companion.
「急ぐあまり歩幅が自然に広くなった。」 means “As I hurried, my stride naturally grew longer.” 自然に marks the stride's natural lengthening while hurrying.
Read deliberate adjustment and 自然に
Matching a companion and a naturally changing stride have different stated explanations.
Speed and step length are different quantities; no calculation formula or universal work rule is supplied.
Does 歩幅 naturally lengthening with 自然に establish a plan to lengthen it?
Show the answer and why
No such plan is stated. The change arose naturally while hurrying, unlike the deliberate shortening to match a companion.