true. when they say that their arms are weak, and if it is, how actually weak to you think they are?
Their arms are obviously strong enough to be used to build advanced space craft, operate machinery and fire weapons (maybe they use thought controlled machinery or droids to do the assembling who knows, but this still means that they would had had to use their arms to build these assembling droids in the first place - the very first one would have had to be built somehow and obviously since it is being built it wouldn't be there to be used to help). So I'm thinking that their arms are stronger than a human child's, but weaker than a human teenager. Their general maximum arm strength (for the ordinary, untrained, less trained and un-mutated/nonspecial-gifted-gene ones) are probably about as strong as a 11 year old girls arms. the builders and such due to conditioning and constant work exercise would probably have stronger arms, as with the warriors and such - but still weaker than a human adults arms. Ax is a andalite child, and his arms were weaker then all the animorphs who were human childs. So an andalite adult in his prime would probably be about as strong as a 12 year old girls arms, and the trained warriors a 14 year old boys arm. Strong, still useful and practical, but still nowhere near the strength of their equivalent human adult in their prime.
lol thats my simple and literal way of looking at it.