Notwithstanding the connection between your question and ELU, there are two considerations and I have one comment.
The first is that any speaker of English will understand the phrase ‘is equal to saying’.
The second is that the expression comes across slightly strangely. This is partly because phrases that include ‘equal to ...’ are usually about someone’s capability to perform some task. “I am /am not equal to (or ‘up to’) marking all these papers you have given me”.
Partly, it is because there are more widely used ways to say what you are saying: ‘...equivalent to saying ...’ or ‘the same as saying...’
My comment is about the use of the word gerund. It has become popular to call the ‘-ing’ form of a verb a participle, when it is used as an adjective, and a gerund, when used as a noun. It’s wide usage in this way makes it impossible to say it is wrong.
BUT the language from which the word ‘gerund’ originates, Latin, has a distinct form for the noun form of a verb: the ending ‘-ndum’. the sentence I must go can be expressed as eundum est mihi (literally, ‘there is a going to me’ or ‘I have a going to do’ŷ. So we get the word ‘gerund. If you were trying to say the same thing in Latin, you would not use a gerund: you would use an infinitive, as you could (just about) in English. And, as far as I am aware, in the sentence seeing is believing we would not call the two -ing words gerunds, just on the basis that they are being used as subject and noun complement. We have simply decided to use the participle form as a noun.
None of this prevents you from from using the phrasing you propose, with or without the small improvement I suggested at the beginning.