Differences between dependencyManagement and dependencies in maven for "provided" scope

I referred to this thread differences between dependencymanagement and dependencies in maven but this question is specific.

Parent POM:

<dependencyManagement>
  <dependencies>
    <dependency>
      <groupId>com.company.rtdp.rtds</groupId>
      <artifactId>rtds-client</artifactId>
      <version>${rtdp.rtds-client.version}</version>
      <!-- SCENARIO 1 : Either give scope here in parent POM -->
      <!-- <scope>provided</scope> -->
    </dependency>
  </dependencies>
</dependencyManagement>

<rtdp.rtds-client.version>1.4.6</rtdp.rtds-client.version>

Child POM:

 <dependencies>
    <!-- SCENARIO 2
    <dependency> 
        <groupId>com.company.rtdp.rtds</groupId> 
        <artifactId>realtimedataserv-client</artifactId> 
        <version>1.4.6</version>
        <scope>provided</scope> 
    </dependency> 
    -->

    <dependency> 
        <groupId>com.company.idi</groupId> 
        <artifactId>idi-persistence</artifactId>
        <version>3.3</version>
        <!--  has a dependency of com.company.rtdp.rtds:rtds-client:jar:1.4.6:compile -->
    </dependency>
 </dependencies>

<!-- SCENARIO 1: OR give scope here in child POM 
<dependencyManagement>
  <dependencies>
    <dependency>
      <groupId>com.company.rtdp.rtds</groupId>
      <artifactId>rtds-client</artifactId>
      <version>1.4.6</version>
      <scope>provided</scope> 
    </dependency>
  </dependencies>
</dependencyManagement>
-->

rtds-client is a transitive dependency of many artifacts out of which idi-persistence is one of them. I want to exclude 1.4.6 in all of the transitive dependencies since I am going to include a different artifact rtds-framework-client (different artifact name) explicitly which is backward compatible to 1.4.6 with <dependency> in child POM.

If have to use <exclusion> I have to explicitly give this in all the dependencies. So, I have decided to go <scope>provided</scope> way.

Known info of Maven based on which my question follows:

If I include the following in child POM (with a version higher than 1.4.6, then rtds-client in all transitive dependencies gets shifted to 1.8. I could see this from 'Dependency Hierarchy' of Eclipse which says 'omitted for conflict with 1.8' [compile]) which means it considers/overrides the version specified in child POM (idi-persistence now gets 1.8).

<dependency>
    <groupId>com.company.rtdp.rtds</groupId>
    <artifactId>rtds-client</artifactId>
    <version>1.8</version>
</dependency>

Question:

If I include the following in child POM without <dependencyManagement> around:

<dependency>
    <groupId>com.company.rtdp.rtds</groupId>
    <artifactId>rtds-client</artifactId>
    <version>1.4.6</version>
    <scope>provided<scope>
</dependency>

None of the rtds-client which comes as transitive dependency considers provided scope whereas I mention the same in a <dependencyManagement> tag either in parent or child POM, provided scope gets applied.

Why version gets affected but not scope given inside <dependency> tag and for scope (for this kind of use case) I have to go for <dependencyManagement> ?

Say if this is allowed, what problem it would lead us into ?

EDIT:

i) <scope>provided with <dependencyManagement>/<dependencies>/<dependency> either in child or parent POM:

Though the longer path is omitted, it says [provided],here.

[INFO] +- com.company.idi:idi-persistence:jar:3.3:compile
[INFO] |  +- com.company.rtdp.rtds:realtimedataserv-client:jar:1.4.6:provided

ii) <scope>provided with direct <dependencies>/<dependency> in child POM without <dependencyManagement> around :

Though the longer path is omitted, it does not say provided and just compile alone.

[INFO] --- maven-dependency-plugin:2.3:tree (default-cli) @ read-rest-service ---
[INFO] +- com.company.rtdp.rtds:realtimedataserv-client:jar:1.4.6:provided (scope not updated to compile)