Tab-Index for absolutely positioned elements in layout

Question

Tab Index for Absolute-Position Elements

For the time being, lets assume I wrote the code below:

    <header class="header hap" [ngClass]="authority">
        <div class="header-inner">
            <div class="header-identity">
                <a id="theLogo" class="logo" [routerLink]="[links.home]" title="Navigate to Home">
                    <img src="assets/logo-white.svg" alt="Logo">
                </a>
                <span class="client-logo" *ngIf="user.brandingImage && !user.isTheAdmin()">
                    <img class="brandingImage" [src]="user.brandingImage" [alt]="user.brandingName" onerror="this.style.display='none'">
                </span>
                [ more links ]
            </div>
            <nav class="main-nav for authenticated" [ngClass]="{'active':showMenu, 'app-only':!isCurrPageAdminApp()}">
                <button class="menu" (click)="toggleMenu()">Menu</button>
                <div class="main-nav-flyout" *ngIf="showMenu">
                    <div class="nav-header">
                        <ul>
                            <li>
                                <a id="main-nav-profile" [routerLink]="['/profile']"><span class="icon icon-user2"></span> My Profile</a>
                            </li>
                            [ more dropdown items ]
                        </ul>
                        <a id="main-nav-close" class="close"(click)="onClickMenuClose()"><span class="icon-cross"></span></a>
                    </div>
                    <div class="nav-body">
                        <ul *ngIf="isCurrPageAdminApp()" class="main-nav-list">
                            <li class="current-app">Administrative Tools</li>
                            <li><a id="main-nav-xAdmin" *ngIf="user.isTheAdmin()" [routerLink]="['admin/x']">X Admin</a></li>
                            [ more links ]
                            <li>
                                <span>Reports</span>
                                <ul>
                                    <li class="user-status"><a id="main-nav-userStatusReport" [routerLink]="['admin/reports/userStatus']">User Status</a></li>
                                    [ more links ]
                                </ul>
                            </li>
                        </ul>
                        <ul class="app-list" *ngIf="user.userApplications">
                            <li *ngIf="showTheLink()">
                                <a id="app-list-type" [routerLink]="['/']">
                                    ...
                                </a>
                            </li>
                            [ more links ]
                            <li *ngFor="let application of user?.userApplications">
                                <a id="app-list-{{application.abbreviation}}" *ngIf="!isAdminApp(application)" (click)="onClickMenuItem(application)">
                                    {{ application.title }}
                                </a>
                            </li>
                        </ul>
                    </div>
                </div>
            </nav>
            <nav class="user-nav for authenticated" role="menu">
                <span *ngIf="user.brandingName" class="user-location">{{user.brandingName}}</span>
                <span *ngIf="user.brandingName" class="pipe">|</span>
                <a id="user-nav-profile" class="user-name" [routerLink]="['/profile']">
                    <span class="name">{{user?.firstName}} {{user?.lastName}}</span>
                </a>
                <a id="user-nav-logout" class="logout" [routerLink]="['/', 'logout']">Log out</a>
            </nav>
        </div>
    </header>

Issue

Various elements -- probably .header-inner > * -- are styled using position: absolute;, so the tabindex-order is skewed for elements which are declared later in the markup but positioned geometrically earlier in the layout.

Question

Is there a way to force the tabindex to be, say, all natural indices (0) except for 2 items that need to be switched -- in a scalable way while not having to implement tabindex for every new item in the layout?