The number of staff members is only four.re are only four staff members

Despite or rather becausethe fact that they weare only four, they almost always complained about their colleagues.

None of them could escape criticisms from theeach other three.

Two months ago, one of my staff members suddenly had to take a temporary leave of absence because of mental illness.

It was because our work is a little specialadvance and anyone who works with us needs to be trained hard in advaexperience.d

TheDuring first week, all of uswe were nervous as well as tired, so asbecause we had to do our job with no mistakes.

TheDuring second week, we gradually came to get accustomed to how to work with a vacancy.

TheDuring third week, we even came to be able to deal with working with one more vacancy.

Now, no one criticizes others.d

They are lively working work was lively, even with a relaxed smile.

The number of staff members is only four.

There are only four staff members.

Despite, or rather because, theyre were only four of them, they almost always complained about their colleagues.

I had been worried about that situation, but I couldn't find any effective solution.

The others and Irest of us decided to keep working without her, rather than temporarily employing someone temporarily.

It waWe decided this because our work is a little specialized and anyone who works with us needs to be trained hardextensively in advance.

The first week, all of us were nervous as well as tired, so as because we had to work hard to do our job with no mistakes.

The second week, we gradually came to gegot accustomed to how to work with a vacancy.

The third week, we even camelearned to be able to deal withhandle working with one more vacancy.

Does this mean there were only two employees now? Someone else left?

They are lively working, even with a relaxed smile.

Since you are one of them, "We" would be more effective.

SI am sorry to say, that the absent staff member has to leave for another couple of months, but the other staff members don't complain about this situation.

They seem to be confident with themselves to keep working until she will come back.

We would be better here too, since you are among them.

You can't really decide what is good and what is bad.

This sentence makes sense, but I'm not sure the context or meaning of it in the larger paragraph.

I deepsincerely hope that the absent staff member will get something goodbetter, too.

There Aare Many Sides to Things

The number ofre are only four staff members is only four.

Despite or rather because theyre were only four of them, they almost always complained about their colleagueseach other.

残念ですね！

I had been worried about thate situation, but I couldn't find any effective solution.

The others and Irest of us decided to keep working without her, rather than temporarily employing someone else.

It wa's because our work is a little special and anyone who works with us needs to be trained hardthoroughly in advance.

The first week, all of us were nervous as well as tired, so as to do our job with no as we tried very hard to avoid mistakes.

Everyone kept an eye on the wholentire flow of the job,work and helped each other.

The second week, we gradually became to get accustomed to how to working with a vacancy.

The third week, we even came to bewere even able to deal with working with one moreanother vacancy.

Now, no one criticizes each others.

They are lively when they are working, and even work with a relaxed smiles.

SI'm sorry to say, the absent staff member has to leave for another couple of months, and yet the other staff members dohaven''t complained about ithis situation.

They seem to be confident with themselves to keep working until she will come backhat they can continue working without her until she returns.

The number of staff members is only four.

Or:
"There are only four staff members"

Despite or rather bBecause they were are only four, they almost always complained about their colleagues.

Your tenses are a little confusing to me, in the last sentence you were in the present tense, but now you're talking in the past tense.

None of them couldan escape criticism from the other three.

I had beenwas worried about thate situation, but I couldn't find any effective solution.

The others and IWe decided to keep working without her, rather than temporarily employing someone.

It wais because our work is a little specialunique and anyone who wants to works with us needs to be trained hard in advance.

The first week, all of us were nervous as well asnd tired, so as to do our job with no mistakes.

I'm a little confused with your sentence, I think it's a little clearer if you write it like this:

"The first week, we worked ourselves to exhaustion, so as to do our job with no mistakes."

Everyone kept an eye on the whole flow of the jobflow, and helped each other.

The second week, we gradually became to get accustomed to how to working with a vacancy.

The third week, we even became to be able to deal withbetter at working with one mormore than one vacancy.

They are lively working lively, even with a relaxed smile.

Sorry to saUnfortunately, the absent staff member has to leave for another couple of months, but the other staff members don't complain about this situation.

They seem to be confident with themselves to keepin working until she will comes back.

I deeply hope that the absent staff member will get something good,something good will happen to the absent staff member too.

Despite or rather because they were only four, they almost always complained about their colleagues.

I don't think it's correct to use despite or rather,
You can also use "as" they where...

It was because our work is a littlesomehow special and anyone who works with us needs to be trained hard in advance.

The first week, all of us were nervous as well as tired, so as to do our job with no mistakes.

They seem to be confident with themselves to keep working until she will comes back.

Present form is used after until