Overusing “and” and how to fix it

Question

Several months ago, I was writing a fan-fiction story set in the Sonic the Hedgehog universe and I ended up constructing this sentence:

"...Sonic and his allies and Dr. Robotnik and his allies..."

My intent here is to group Sonic and Sonic's allies together and Dr. Robotnik and Dr. Robotnik's allies together, but doing so with "and"s causes this problem. I fixed it by replacing the second "and" with "versus", thus reading as:

"...Sonic and his allies versus Dr. Robotnik and his allies..."

My question is: is the original construction still valid?

I'm also curious about my usage of "his" to refer to two different males in a row.

Answer 1

As long as the sentence is grammatical, it's technically valid! Even this is a meaningful and grammatical sentence, although it may take a few readings to see how:

Buffalo buffalo buffalo buffalo buffalo buffalo buffalo buffalo.

Since the original is valid, the primary concern is readability. While your readers will often figure out what you mean from context, they won't always be able to. In this example, it would be strange for Sonic and Dr. Robotnik to be on the same side, although it would not be impossible; just look at Mario and Wario!

One solution would be to separate with commas, although that might be grammatically controversial:

Sonic and his allies, and Dr. Robotnik and his allies, went to...

Usually, when I find myself writing a sentence that I'm concerned is too ambiguous, I will try completely re-phrasing it. For example:

Sonic and his allies went with Dr. Robotnik and his allies...
Sonic, Dr. Robotnik, and their [respective] allies...