run the script according to logical conditions in R

In my data set, I work with groups(stratum) SKU-acnumber-year. Here little example:

df=structure(list(SKU = c(11202L, 11202L, 11202L, 11202L, 11202L, 
11202L, 11202L, 11202L, 11202L, 11202L, 11202L, 11202L, 11202L, 
11202L, 11202L, 11202L, 11202L, 11202L, 11202L, 11202L, 11202L
), stuff = c(8.85947691, 9.450108704, 10.0407405, 10.0407405, 
10.63137229, 11.22200409, 11.22200409, 11.81263588, 12.40326767, 
12.40326767, 12.40326767, 12.99389947, 13.58453126, 14.17516306, 
14.76579485, 15.94705844, 17.12832203, 17.71895382, 21.26274458, 
25.98779894, 63.19760196), action = c(0L, 0L, 0L, 0L, 0L, 0L, 
0L, 0L, 0L, 0L, 1L, 0L, 0L, 0L, 0L, 0L, 0L, 0L, 0L, 1L, 1L), 
    acnumber = c(137L, 137L, 137L, 137L, 137L, 137L, 137L, 137L, 
    137L, 137L, 137L, 137L, 137L, 137L, 137L, 137L, 137L, 137L, 
    137L, 137L, 137L), year = c(2018L, 2018L, 2018L, 2018L, 2018L, 
    2018L, 2018L, 2018L, 2018L, 2018L, 2018L, 2018L, 2018L, 2018L, 
    2018L, 2018L, 2018L, 2018L, 2018L, 2018L, 2018L)), .Names = c("SKU", 
"stuff", "action", "acnumber", "year"), class = "data.frame", row.names = c(NA, 
-21L))

Very important:

The action column has only two values 0 and 1. As we can see in this example there is 3 observations by stuff of 1 category of action and 18 obs by stuff of zero category.

I need set logic condition. so, for groups which have from 1 to 4 observations by stuff of 1 category of action, then run script1.r

and for groups which have >=5 observations by stuff of 1 category of action then must be run script2.r

I would imagine it in this way, the script3.r is created, with the following content(condition), but I do not know how to correctly set these logical conditions.

# i take data from sql
dbHandle <- odbcDriverConnect("driver={SQL Server};server=;database=;trusted_connection=true")
sql <- paste0(select needed columns)
df <- sqlQuery(dbHandle, sql)



   for groups where from 1-4  observations by stuff of 1 category of action then  C:/path to/скрипт1.r
(or if  groups have from 1-4  observations by stuff of 1 category of action then  C:/path to/script1.r)
    for  groups   where >=5 observations by stuff of 1 category of action then C:/path to/script2.r
( of if groups  have >=5 observations by stuff of 1 category of action then C:/path to/script2.r)

How do I implement this? the script.3r runs by schedule, it will work according to the schedule, in order to run two scripts. I just do not want to make my Shedule for each script seaprately.