The parable of the faithful slave vs wicked slave (appearing in Matt 24 and Luke 12, aka double tradition) has consumed a whole lot of bandwidth here. Setting that particular parable aside for the moment lets look at the parallel parable of the talents/minas in (Matt 25:14-30 and Luke 19:11-27, also double tradition, not found in Mark)
Mattews version:
14 “For it is just like a man about to go on a journey, who called his own slaves and entrusted his possessions to them. 15 To one he gave five [a]talents, to another, two, and to another, one, each according to his own ability; and he went on his journey. 16 Immediately the one who had received the five talents went and traded with them, and gained five more talents. 17 In the same manner the one who had received the two talents gained two more. 18 But he who received the one talent went away, and dug a hole in the ground and hid his [b]master’s money.
19 “Now after a long time the master of those slaves *came and *settled accounts with them. 20 The one who had received the five talents came up and brought five more talents, saying, ‘Master, you entrusted five talents to me. See, I have gained five more talents.’ 21 His master said to him, ‘Well done, good and faithful slave. You were faithful with a few things, I will put you in charge of many things; enter into the joy of your [c]master.’
22 “Also the one who had received the two talents came up and said, ‘Master, you entrusted two talents to me. See, I have gained two more talents.’ 23 His master said to him, ‘Well done, good and faithful slave. You were faithful with a few things, I will put you in charge of many things; enter into the joy of your master.’
24 “And the one also who had received the one talent came up and said, ‘Master, I knew you to be a hard man, reaping where you did not sow and gathering where you scattered no seed. 25 And I was afraid, and went away and hid your talent in the ground. See, you have what is yours.’
26 “But his master answered and said to him, ‘You wicked, lazy slave, you knew that I reap where I did not sow and gather where I scattered no seed. 27 Then you ought to have put my money [d]in the bank, and on my arrival I would have received my money back with interest. 28 Therefore take away the talent from him, and give it to the one who has the ten talents.’
29 “For to everyone who has, more shall be given, and he will have an abundance; but from the one who does not have, even what he does have shall be taken away. 30 Throw out the worthless slave into the outer darkness; in that place there will be weeping and gnashing of teeth.
Luke's version:
12 So He said, “A nobleman went to a distant country to receive a kingdom for himself, and then return. 13 And he called ten of his slaves, and gave them ten [a]minas and said to them, ‘Do business with this [b]until I come back.’ 14 But his citizens hated him and sent [c]a delegation after him, saying, ‘We do not want this man to reign over us.’ 15 When he returned, after receiving the kingdom, he ordered that these slaves, to whom he had given the money, be called to him so that he might know what business they had done. 16 The first appeared, saying, ‘[d]Master, your [e]mina has made ten minas more.’ 17 And he said to him, ‘Well done, good slave, because you have been faithful in a very little thing, you are to be in authority over ten cities.’ 18 The second came, saying, ‘Your [f]mina, [g]master, has made five minas.’ 19 And he said to him also, ‘And you are to be over five cities.’ 20 Another came, saying, ‘Master, here is your mina, which I kept put away in a handkerchief; 21 for I was afraid of you, because you are an exacting man; you take up what you did not lay down and reap what you did not sow.’ 22 He *said to him, ‘[h]By your own words I will judge you, you worthless slave. Did you know that I am an exacting man, taking up what I did not lay down and reaping what I did not sow? 23 Then why did you not put my money in the bank, and having come, I would have collected it with interest?’ 24 Then he said to the bystanders, ‘Take the mina away from him and give it to the one who has the ten minas.’ 25 And they said to him, ‘Master, he has ten minas already.’ 26 I tell you that to everyone who has, more shall be given, but from the one who does not have, even what he does have shall be taken away. 27 But these enemies of mine, who did not want me to reign over them, bring them here and slay them in my presence.”
This parable is an example of editorial fatigue. The writer of Luke obviously has Matt in view when including this parable. Matt's expansion on Mark 13:34 is emulated by Luke but he has made some changes to his source material. The first obvious change is to alter Matt's 3 servants to 10. The trust money also changes. The unit of money aside, (60 minas to a talent) in Matt each gets according to ability 5,2 and 1. Whereas in Luke each of the ten gets 1. The conclusion is also different in that in Matt the first servant made 5 more from the 5 (total 10) and gets rewarded with authority over "many things" and the second made 2 more with the 2 (total 4) and also rewarded with "many things", whereas in Luke (who had 10 servants now agrees with Matt in having only 3 in the summary). The first made 10 more with his 1 (11 total) and is rewarded with 10 cities the second made 5 more with his one (6 total) and receives 5 cities. And another has not not done anything.
So while Luke made changes to Matt he retained certain elements that make his version rather awkward in comparison. Why 10 servants but only 3 get mention? The conclusion is also telling:
Luke....‘Take the mina away from him and give it to the one who has the ten minas
Matt.....take away the talent from him, and give it to the one who has the ten talents.
Here Luke has copied Matt (his source) without noticing this causes a problem due to his changes. The reward of ten monetary units makes less sense in Luke as he has the first slave have 11 and gets 10 cities as a reward. It is only in Matt that the first slave gets rewarded with 10 units of money.
Again this an example of editorial fatigue. Luke, for his own reasons, makes changes to his source Matt but by the end has reverted to more closely follow Matt even though this makes his reading less coherent.
There are many examples like this.
Goodacre did a nice article on this: https://markgoodacre.org/fatigue.pdf