There is a guideline called 'monster rank'.
These ranks indicate the strength and wonder of monsters, and are represented by symbols that correspond to adventurer ranks.

For example, the monster rank of a common goblin is H-rank.
This means that the monster is two ranks lower than the average rank of an F-rank adventurer who has just registered as an adventurer.

In general, the strength of a monster doubles for each rank increase.
Here, double means that two monsters of a certain rank are equal in threat to one monster of a higher rank.
However, for the sake of convenience, we use the term "double" to mean the strength of two monsters.

In this sense, an F-rank adventurer is four times as strong as an H-rank goblin.
In other words, one F-rank adventurer is evenly matched against four goblins.
This is a very rough way of putting it, but it can be considered as a rough indicator.

However, no F-rank adventurer would actually try to fight four goblins by himself, even if they were evenly matched.
This is because exchanging lives with an evenly matched opponent means a 50-50 chance of dying.

To reduce the risk of losing your life, a good adventurer will have a certain buffer of strength, or margin.
The system for accepting quests from the Adventurer's Guild takes this margin into account to some extent.

Take, for example, the quest to exterminate goblins.
A single goblin pack often consists of about 20 goblins, and four F-rank adventurers and 20 goblins would give the adventurers a disadvantage in terms of strength.

However, since the adventurers do not usually fight 20 goblins in a single battle, but rather use the tactic of defeating each goblin individually, it is likely that four F-rank adventurers will be able to handle the situation to some extent, even if it is a case-by-case basis.

In general, it is advisable to have double or quadruple the strength of the party.
A party of four F-rank adventurers should be able to take on four to eight goblins at once.
Of course, there is always room for more, but if you have that kind of ability, you might as well take a quest with a higher rank and better rewards.

However, I personally disagree with the doubling of the level.
According to the author of a book I like, who survived as an adventurer for about 30 years until he retired at the age of 46, the level of double is the one where people frequently lose their lives due to a small mistake, bad luck, or accident.

Incidentally, it is said that the books he wrote about his adventures were not well received.
It seems that people are looking for bloody and exciting adventure stories that have been greatly adapted, and not for his careful and steady style of writing about the life of an adventurer.
I disagree with this opinion of the world at all, because I am attracted to the reality without any fancy, but that's beside the point.

But I digress. Anyway, the contrast between the strength of adventurers and monsters should usually be considered with a certain margin in mind.

Now, let's get down to business.
This is about goblin lords.

The goblin lord's monster rank is E.
This means that an ordinary F-rank adventurer would have to take on two Goblin Lords to be on par with them, and four would be the minimum strength level.

However, if by "ordinary F-rank adventurers" you mean mages who have flunked out of the academy and are in the beginner class, or adventurers who have the same level of skill as mages, then at least I am not at that level.

And one more person... Satsuki.
If we are to believe Cyril's words, she is also a very skilled adventurer.
How good is she?

'Satsuki, I have a question.

As I was walking to the last hall, I stopped by Satsuki's side and whispered into her ear.

'What is it, William? It's close, it's close.

'The enemy's base is close by. We can't talk too loudly.'

I said to Satsuki, whose cheeks were blushing, as if she had misunderstood something.

'...... I see. And what's that?

'Can you beat the Goblin Lord in a one-on-one fight?'

I'll ask him straight out first.
His perception can be important information, even if we can't take it on faith.
But Satsuki's response to that was...

'Well, I don't know. I've never tried it, and I don't even know how a goblin lord is different from a goblin.

I see.
If you don't know what a goblin lord is, it's not a good basis for judgment.

Then let's change the question. Can Satsuki fight eight goblins by herself and win?

This is a very crude way of thinking about things.
Eight H-rank goblins and an E-rank goblin lord are equivalent.
However, even though there are various problems, it can serve as a guideline.

'Huh? Eight goblins? I'm the only one who can do that at once?

'Yeah.

'That's...'

Satsuki put her hand to her chin and looked diagonally upward, as if she was imagining something.
And then..,

'It'll be easy. It's no big deal.

'......'

Satsuki assured him.
It didn't seem like she was being tough.
It was a completely natural and confident reply.

Interesting.

Then change of plans.
Knowing exactly how powerful she is will be an important and valuable piece of information for our future adventures as a party with her.
It would be worth the risk to acquire this information.

'Satsuki, you said you wanted a chance to clear your name.

'Yeah. I think I said something to that effect.

'Then let's see it in the next battle. Only the Goblin Lord will be left. Let's see what you can do.''

When I said that, Satsuki stopped and looked at me with a stunned expression.

'...... You know what, William?

'Hmm, what is it?

'Were you by any chance planning to end your fight with the boss by putting him all to sleep?

Satsuki looked dumbfounded.
Then you realize that's where it's coming from.

'Well, I was planning to take out various other insurance policies. You're generally right.

'Hahaha ...... ah, yes ......'.

Satsuki showed a flinching expression at my reply.