から言(い)うとSpeaking in terms of, From the point of view of

から言うと and から見ると both express viewpoint, but differ in nuance. から言うと emphasizes interpretation or judgment from language or opinion, e.g. 経験から言うとそれは無理だ ('Speaking from experience, that's impossible'). から見ると highlights observation or appearance, e.g. 外国人から見ると奇妙に見える ('From a foreigner's perspective, it appears strange').

から言うと and にしたら both express perspective, but differ in nuance. から言うと gives an opinion or evaluation from a stated viewpoint, e.g. 医者から言うとこれは異常だ ('From a doctor's perspective, this is abnormal'). にしたら puts the speaker in someone else's position to make a subjective judgment, e.g. 子供にしたら怖かっただろう ('It must have been scary from the child's perspective').

から言うと and からすると・からすれば are similar in that both introduce perspective. から言うと explicitly means 'speaking from (A)', offering a basis for opinion, e.g. 経験から言うと簡単ではない ('Speaking from experience, it's not easy'). からすると・からすれば has a broader 'based on (A)' meaning, often implying inference, e.g. 態度からすると反省していない ('Judging from his attitude, he isn't sorry').

ことから and から言うと both express basis or reasoning, but differ in tone and usage. ことから is generally used for factual inference or deduction, e.g. 電気が付いていないことから、誰もいないと分かった ('Judging from the fact the lights are off, I could tell no one is there'). から言うと provides a basis for a stated opinion, e.g. 経験から言うと注意が必要だ ('Speaking from experience, caution is required').

で言うと and から言うと both present a frame of reference, but differ in nuance. で言うと highlights category or classification, often for comparison, e.g. 車で言うとポルシェみたいなものだ ('If we speak in terms of cars, it's like a Porsche'). から言うと gives a basis for a stated opinion, e.g. 私の経験から言うと、もうどうしようもない ('Speaking from my experience, there's nothing to be done').

から言うと and 上 both indicate viewpoint, but から言うと introduces a subjective opinion from a specific angle, e.g. 学生の立場から言うと反対だ ('Speaking from a student's viewpoint, I'm against it'). 上 expresses evaluation based on a defined category, e.g. 法律上問題はない ('There's no problem in terms of the law').